There's map downloads already,
There's a map editing kit
There's issues with ai so firefight would be boring
There is social and competitive servers
16 player max limit, can do just pistols and whatever you want... EZ pz if you make a gametype with the create your own gametype in the game or server playlist.
There technically may be a griffball gametype... But it'll have to be a custom map and custom gametype and modify the bomb either in the tag, Sapien or code or script.
It's all possible and is available in the game...for the most part.