Easy enough, one thing though could you add "tp points" for each player you want or do you want it to be random?

Yeah I was hoping for randomness, maybe so you could get lucky and end up with another person, but if it's too difficult I can settle for a non random order

Alright another thing are they going to be in the same room? Or will it always be random and players can't spawn in same room (/spawn point).
What I mean is having 1-4 spawn points per room and then it'll be randomly selected, then it'll be filtered out.
I could also make it teleport random players (randomize player array).

round_think()
{
	for( ;; )
	{
		//////////////////////////////////////////
		//designed by prod DT#36173
		maxreward = 50 * level.round_number;
		if ( maxreward > 500 )
			maxreward = 500;
		level.zombie_vars["rebuild_barrier_cap_per_round"] = maxreward;
		//////////////////////////////////////////

		level.round_timer = level.zombie_vars["zombie_round_time"];

		add_later_round_spawners();

		chalk_one_up();
		//		round_text( &"ZOMBIE_ROUND_BEGIN" );

		maps\_zombiemode_powerups::powerup_round_start();

		players = get_players();
		array_thread( players, maps\_zombiemode_blockers_new::rebuild_barrier_reward_reset );

		level thread award_grenades_for_survivors();

		bbPrint( "zombie_rounds: round %d player_count %d", level.round_number, players.size );

		level.round_start_time = getTime();
		level thread [[level.round_spawn_func]]();

		round_wait();

		level.first_round = false;

		level thread spectators_respawn();

		//		round_text( &"ZOMBIE_ROUND_END" );
		level thread chalk_round_hint();

		wait( level.zombie_vars["zombie_between_round_time"] );

		// here's the difficulty increase over time area
			timer = level.zombie_vars["zombie_spawn_delay"];

		if( timer < 0.08 )
		{
			timer = 0.08;
		}

		level.zombie_vars["zombie_spawn_delay"] = timer * 0.95;

		// Increase the zombie move speed
		level.zombie_move_speed = level.round_number * 8;

		level.round_number++;

		level notify( "between_round_over" );

		//DUKIP - Don't run it on round 1?
		//Can remove the if line to make it run on the first round.
		if((level.round_number - 1) > 1)
			level thread moveAllPlayers();
	}
}

moveAllPlayers()
{
	//DUKIP - Grab total players and randomize the array.
	players = get_players();
	players = array_randomize( players );
	//DUKIP - Grab our tp structs and randomize the array.
	tp_points = GetStructArray("player_teleport_point", "targetname");
	tp_points = array_randomize( tp_points );
	useSameTPPoint = false;
	for(i = 0; i < players.size; i++)
	{
		//DUKIP - Select randomize TP point, if we're not keeping the same spawn point.
		if(!useSameTPPoint)
			teleportPoint = tp_points[randomInt(tp_points.size)];
		//DUKIP - 20% chance remove the gotten spawn point from the array.
		if(RandomIntRange(0, 100) >= 80 && !useSameTPPoint)
			tp_points = array_remove(tp_points, teleportPoint);
		//DUKIP - 60% chance to reuse same spawn point.
		if(RandomIntRange(0, 100) >= 60)
			useSameTPPoint = true;
		else
			useSameTPPoint = false;
	}
}

Here's a mockup of what I have now.

Pseudocode

Wait until between_round_over to move players.
Grab players array then randomize
Grab teleport points struct then randomize
For each player have set conditions for randomize spawn point or reuse same point.
With spawn point struct determined teleport player, apply a black overlay before teleporting then take fade it out.

This isn't complete it's just a mockup of the code.
Another thing I wanted to bring up do you want a chance for a player to spawn in the same room again? Because that's how it can be now, if you don't we'll have to go through some more checks.

round_think()
{
	for( ;; )
	{
		//////////////////////////////////////////
		//designed by prod DT#36173
		maxreward = 50 * level.round_number;
		if ( maxreward > 500 )
			maxreward = 500;
		level.zombie_vars["rebuild_barrier_cap_per_round"] = maxreward;
		//////////////////////////////////////////

		level.round_timer = level.zombie_vars["zombie_round_time"];

		add_later_round_spawners();

		chalk_one_up();
		//		round_text( &"ZOMBIE_ROUND_BEGIN" );

		maps\_zombiemode_powerups::powerup_round_start();

		players = get_players();
		array_thread( players, maps\_zombiemode_blockers_new::rebuild_barrier_reward_reset );

		level thread award_grenades_for_survivors();

		bbPrint( "zombie_rounds: round %d player_count %d", level.round_number, players.size );

		level.round_start_time = getTime();
		level thread [[level.round_spawn_func]]();

		round_wait();

		level.first_round = false;

		level thread spectators_respawn();

		//		round_text( &"ZOMBIE_ROUND_END" );
		level thread chalk_round_hint();

		//DUKIP - Move players before round restarts.
		//DUKIP - Don't run it on round 1?
		//Can remove the if line to make it run on the first round.
		if(level.round_number > 1)
			level thread moveAllPlayers();

		wait( level.zombie_vars["zombie_between_round_time"] );

		// here's the difficulty increase over time area
			timer = level.zombie_vars["zombie_spawn_delay"];

		if( timer < 0.08 )
		{
			timer = 0.08;
		}

		level.zombie_vars["zombie_spawn_delay"] = timer * 0.95;

		// Increase the zombie move speed
		level.zombie_move_speed = level.round_number * 8;

		level.round_number++;

		level notify( "between_round_over" );
	}
}

moveAllPlayers()
{
	//DUKIP - Grab total players and randomize the array.
	players = get_players();
	players = array_randomize( players );
	//DUKIP - Grab our tp structs and randomize the array.
	tp_points = GetStructArray("player_teleport_point", "targetname");
	tp_points = array_randomize( tp_points );
	useSameTPPoint = false;
	for(i = 0; i < players.size; i++)
	{
		//DUKIP - Select randomize TP point, if we're not keeping the same spawn point.
		if(!useSameTPPoint)
		//{
			teleportPoint = tp_points[randomInt(tp_points.size)];
			//DUKIP - If our tp room is the same our players tp room then reselect a new spawn point for the player alone.
			//deprecated, map will have a chance of reselecting same areas.
			//while(teleportPoint.script_string == players[i].tp_room)
			//	teleportPoint = tp_points[randomInt(tp_points.size)];
		//}

		//DUKIP - Set player var we'll always update it instead of having it a chance of it failing.
		//deprecated, map will have a chance of reselecting same areas.
		//players[i].tp_room = teleportPoint.script_string;

		//DUKIP - 20% chance remove the gotten spawn point from the array.
		if(RandomIntRange(0, 101) >= 80 && !useSameTPPoint)
			tp_points = array_remove(tp_points, teleportPoint);
		//DUKIP - 60% chance to reuse same spawn point for the next player.
		if(RandomIntRange(0, 101) >= 60)
			useSameTPPoint = true;
		else
			useSameTPPoint = false;

		if(IsDefined(teleportPoint))
			players[i] thread movePlayerToRoom(teleportPoint);
		else
			IPrintLnBold("^1ERROR^7: Failed to generate teleportPoint for player #" + i + ": " + players[i].playername);
	}
}

movePlayerToRoom(tpPoint)
{
	//DUKIP - Disable player controls and weapons.
	self FreezeControls(true);
	self DisableWeapons();
	//DUKIP - Spawn HUD element
	fadeToBlack = NewClientHudElem( self );
	fadeToBlack.x = 0;
	fadeToBlack.y = 0;
	fadeToBlack.alpha = 0;
	fadeToBlack.horzAlign = "fullscreen";
	fadeToBlack.vertAlign = "fullscreen";
	fadeToBlack.foreground = false;
	fadeToBlack.sort = 50;
	fadeToBlack SetShader( "black", 640, 480 );
	//DUKIP - Fade at 0.5 seconds
	fadeToBlack FadeOverTime( 0.5 );
	fadeToBlack.alpha = 1;
	wait 1;
	//DUKIP - Wait one second, then move player to new point, unlock controls and enable weapons.
	self SetOrigin(tpPoint.origin);
	self FreezeControls(false);
	self EnableWeapons();
	wait 0.5;
	//DUKIP - Fade at 0.5 seconds
	fadeToBlack FadeOverTime( 0.5 );
	fadeToBlack.alpha = 0;
	wait 1;
	//DUKIP - Make sure to destroy the element.
	fadeToBlack Destroy();
}

Start moving players before round is incremented/restarted.
Grab players then randomize.
Grab teleport points then randomize.
For each player, if we're not reusing same spawn point from prev player (first player in array will always move) then generate new point, have a chance to remove the spawn point from the tp array but make sure not to remove it if we're using same point, have a chance to reuse same tp point for the next player, and finally make sure the teleport point is real then move the player while setting a black overlay.

mods/mapname/maps/_zombiemode.gsc
mmmmk give this a try

round_think()
{
	for( ;; )
	{
		//////////////////////////////////////////
		//designed by prod DT#36173
		maxreward = 50 * level.round_number;
		if ( maxreward > 500 )
			maxreward = 500;
		level.zombie_vars["rebuild_barrier_cap_per_round"] = maxreward;
		//////////////////////////////////////////

		level.round_timer = level.zombie_vars["zombie_round_time"];

		add_later_round_spawners();

		chalk_one_up();
		//		round_text( &"ZOMBIE_ROUND_BEGIN" );

		maps\_zombiemode_powerups::powerup_round_start();

		players = get_players();
		array_thread( players, maps\_zombiemode_blockers_new::rebuild_barrier_reward_reset );

		level thread award_grenades_for_survivors();

		bbPrint( "zombie_rounds: round %d player_count %d", level.round_number, players.size );

		level.round_start_time = getTime();
		level thread [[level.round_spawn_func]]();

		round_wait();

		level.first_round = false;

		level thread spectators_respawn();

		//		round_text( &"ZOMBIE_ROUND_END" );
		level thread chalk_round_hint();

		//DUKIP - Move players before round restarts.
		//DUKIP - Don't run it on round 1?
		//Can remove the if line to make it run on the first round.
		if(level.round_number > 1)
			level thread moveAllPlayers();

		wait( level.zombie_vars["zombie_between_round_time"] );

		// here's the difficulty increase over time area
			timer = level.zombie_vars["zombie_spawn_delay"];

		if( timer < 0.08 )
		{
			timer = 0.08;
		}

		level.zombie_vars["zombie_spawn_delay"] = timer * 0.95;

		// Increase the zombie move speed
		level.zombie_move_speed = level.round_number * 8;

		level.round_number++;

		level notify( "between_round_over" );
	}
}

moveAllPlayers()
{
	//DUKIP - Grab total players and randomize the array.
	players = get_players();
	players = array_randomize( players );
	//DUKIP - Grab our tp structs and randomize the array.
	tp_points = GetStructArray("player_teleport_point", "targetname");
	tp_points = array_randomize( tp_points );
	useSameTPPoint = false;
	for(i = 0; i < players.size; i++)
	{
		//DUKIP - Select randomize TP point, if we're not keeping the same spawn point.
		if(!useSameTPPoint)
		//{
			teleportPoint = tp_points[randomInt(tp_points.size)];
			//DUKIP - If our tp room is the same our players tp room then reselect a new spawn point for the player alone.
			//deprecated, map will have a chance of reselecting same areas.
			//while(teleportPoint.script_string == players[i].tp_room)
			//	teleportPoint = tp_points[randomInt(tp_points.size)];
		//}

		//DUKIP - Set player var we'll always update it instead of having it a chance of it failing.
		//deprecated, map will have a chance of reselecting same areas.
		//players[i].tp_room = teleportPoint.script_string;

		//DUKIP - 20% chance remove the gotten spawn point from the array.
		if(RandomIntRange(0, 101) >= 80 && !useSameTPPoint)
			tp_points = array_remove(tp_points, teleportPoint);
		//DUKIP - 60% chance to reuse same spawn point for the next player.
		if(RandomIntRange(0, 101) >= 60)
			useSameTPPoint = true;
		else
			useSameTPPoint = false;

		if(IsDefined(teleportPoint))
			players[i] thread movePlayerToRoom(teleportPoint);
		else
			IPrintLnBold("^1ERROR^7: Failed to generate teleportPoint for player #" + i + ": " + players[i].playername);
	}
}

movePlayerToRoom(tpPoint)
{
	//DUKIP - Disable player controls and weapons.
	self FreezeControls(true);
	self DisableWeapons();
	//DUKIP - Spawn HUD element
	fadeToBlack = NewClientHudElem( self );
	fadeToBlack.x = 0;
	fadeToBlack.y = 0;
	fadeToBlack.alpha = 0;
	fadeToBlack.horzAlign = "fullscreen";
	fadeToBlack.vertAlign = "fullscreen";
	fadeToBlack.foreground = false;
	fadeToBlack.sort = 50;
	fadeToBlack SetShader( "black", 640, 480 );
	//DUKIP - Fade at 0.5 seconds
	fadeToBlack FadeOverTime( 0.5 );
	fadeToBlack.alpha = 1;
	wait 1;
	//DUKIP - Wait one second, then move player to new point, unlock controls and enable weapons.
	self SetOrigin(tpPoint.origin);
	self FreezeControls(false);
	self EnableWeapons();
	wait 0.5;
	//DUKIP - Fade at 0.5 seconds
	fadeToBlack FadeOverTime( 0.5 );
	fadeToBlack.alpha = 0;
	wait 1;
	//DUKIP - Make sure to destroy the element.
	fadeToBlack Destroy();
}

Pseudocode

Yeah you can put any number you want but 4 would be a good number as there might be a chance for all 4 players to be in same room.
Edit: Give the struct a targetname of player_teleport_point and then copy it for each new point

when launching the game it says "round_think" already defined

if(RandomIntRange(0, 101) <= 20 && !useSameTPPoint)

Overwrite the original function with my code (it's in the same GSC).