Honestly, at this point in time it seems that Treyarch are the only studio that can make a decent COD.
IW haven't made a good COD since MW2 and Infinite Warfare (excluding the campaign) is hands down the worst COD I have played.
Although I enjoyed AW it seems that the community didn't and a lot of people dislike WW2 as well. Plus the helped make the MW3 MP which, whilst being OK, wasn't as good as previous MW games.
For me, Treyarch haven't made a bad COD yet. I never played WaW but all 3 Black Ops games have been absolutely fantastic and the most fun I've had in COD MP.
So Activision should fuck off all the teams apart from Treyarch. Get them releasing a game every 2-3 years and get them constantly updating their current game until the new one is out.