I agree 100000%. I love Combat Training, and still go back and play it to this day. There are several reasons I want them to bring it back.
I am with you, I am hoping they bring it back with improvements (I want to be able to prestige in there, and perhaps play other game types that I wouldn't normally play, ould be a great way to learn them!)
Combat Training should return and the AI players should be able to play on other game modes, not just TDM and FFA. Combat Training was great when I first got the game to run around care free and learn the maps. It was also good for DLC maps. I also used Combat Training for private matches with a small number of people to fill the game with extra players. This also works extremely well for split screen action
According to this:
it's already been confirmed by Treyarch.
I really enjoy CT too.