Epic has Geow and UE3 which is there big money maker but if MS would say ok we dont want you (the developers) use UE3/UE4 for PS3/PS4 it would destroy the whole purpose of the UE3 . Lets think about it UE3 is a multiplat engine It is mainly used for Multiplat game. Thats part of its success. I think that this is the biggest reason for its success because it is good for both platforms.
Most developers wouldnt use it anymore if they cant programm Multiplat titles. So Epic would lose a big part of is value and that would equal a loss to MS. MS knows that so if MS is buying Epic then they definetly let produce them further engines for Playstation products. If MS highers the fees for the use of Epic Engines and adds resrictions like no Multiplat development then Epic would suffer greatly. And maybe all of them would use Cryengine 3 instead of UE3.
Essay Pro