They allready have a 3v3v3 no really much need to go even smaller and just make it a 2v2. For I could see that as a boosters paradise, since no one would ever join in to see the boosting happen and then report it.
Two friends split screening and no one would ever know they were boosting.
So not really a good idea.
It is true it is a boosters paradise but I do agree that I miss the "Face Off" playlist from MW3 me and a friend or me and 2 friends used to love the 2v2 and 3v3 gametype where you can rely on yourself and not the other 3 players on your team having a bad game. If that makes any sense. But I do agree that it could be easily exploited as well.