Yeah, I find it kind of hard to believe that Marvel would really dictate much regarding the Capcom side of things. I'm pretty certain that the roster on their side and its lack of X-men and FF characters, and heavy focus on the MCU, was mostly Marvel's doing though since that was (and still sort of is) their prerogative right now. They may have wanted to push for a more realistic style, but then again, they may have been fine with the look that MvC3 had. Since they're not a game company, I think that they wouldn't have much of an opinion on how Capcom handles things beyond the Marvel roster and representation of those characters in the game. Given how much flak Infinite is getting, I don't think we'll have actual clarification regarding how much input was had by Marvel for a long time.