They removed Clan vs Clan TDM...not sure why or if it will return. They haven't given any answer to this that I have seen. They did add a new game mode (Reinforce) which may have taken it's spot in the list of available game modes.
My guess is that no one plays CvC. Just time one of those lobbies before the match starts. I'd have to say it's the slowest of any game type to begin, by far. I wouldn't be surprised if they eliminate CvC completely.
The load out restrictions made the game very boring and you have 4v4 on huge Ghosts maps. In the end its pretty much a game of hide and seek on a really big field. Not very fun during the times I tried it. You would be lucky to get 10 kills in a match.
The biggest thing our clan misses was the points we earned. You can't earn as many points in regular game modes. Plus we all enjoyed playing with out kill streaks rewards and IEDs. Straight up on your skills v their skills! They need to either bring it back or give something comparable.