Polygon states that the game will be (at least highly expected to be) based on the Marvel Cinematic Universe. As such, there will be no mutants, such as Wolverine and Magneto, which I am very upset Disney did, although some of that may be because of Fox too. Then again, Disney and Capcom previously couldn’t do an agreement just to keep DLC post-2013. This is a very controversial choice as Capcom and X-Men have been together since X-Men: Children of the Atom, and even the SNES X-Men games.
X-Men characters Wolverine, Magneto, Phoenix, Storm, X-23 and Sentinel were playable characters in the last Marvel vs Capcom crossover, while Cable, Scott Summers, etc. were in previous incarnations.