So now thats BO3 is getting modding tools what is this site going to do, will there be a custom BO3 Zomebies section etc?

Over the years, the Call of Duty® community has proven itself to be among the most passionate in the world – and we count ourselves fortunate to make games for you.
We’ve been listening to one of your top requests and are excited to announce that modding and mapping are coming to Call of Duty: Black Ops 3 PC!
We’ve still got a lot of work left to do, but here’s our current plan:
You will be able to create Maps & Game Modes and more!
We will include Unranked Dedicated Server Files with the tools so you can run servers with modded content anywhere you choose.
We will provide an Unranked Server Browser so you can easily find and join servers with modded content.
Closed Alpha target date:  March 2016
Please remember that this is software development, so things don’t always work out exactly as planned.  Sometimes features slip or drop off altogether, sometimes they get replaced with other, more awesome features as we hit into limitations of our original plans.
There is much more news to come including updates on Open Beta timing.  In order to keep you informed, we’ll periodically publish developer blog posts to share our progress with our fans. Stay tuned to the Treyarch blog for more information.
And yes, this is for real.
Sincerely,
Cesar Stastny
Director of Development

https://community.treyarch.com/community/treyarch/blog/2015/11/02/modding-mapping-tools-coming-to-black-ops-3-pc-in-2016

There's already another topic discussing the same thing.

will there be a custom BO3 Zomebies section etc?

Yes

already a topic 

Please remember that this is software development, so things don’t always work out exactly as planned.  Sometimes features slip or drop off altogether, sometimes they get replaced with other, more awesome features as we hit into limitations of our original plans.
Hopefully the mod tools don't get scrapped entirely

Please remember that this is software development, so things don’t always work out exactly as planned.  Sometimes features slip or drop off altogether, sometimes they get replaced with other, more awesome features as we hit into limitations of our original plans.
Hopefully the mod tools don't get scrapped entirely

BO3 is now the 2nd and 3rd best seller on Steam ever since that announcement of mod tools, they backed themselves into a corner if they dare say "sorry we cancelled mod tools" they would be stabbing a bunch of people in the back and would lose many customers.

BO3 is not the 2nd and 3rd best seller on Steam ever since that announcement of mod tools, they backed themselves into a corner if they dare says "sorry we cancelled mod tools" they would be stabbing a bunch of people in the back and would lose many customers.

I highly doubt they would, but i would still expect the usual teething problems and delays at most