I'm actually wondering now, is this Disney/Marvel's subtle hint that they're going after the other studios that're holding onto their film rights? Fox and Marvel haven't always been on the same page, that's no secret. 3 to 4 Marvel Studio films a year is certainly going to cannibalize revenue from the other Marvel films from Fox and Sony. Also consider the fact that Marvel Entertainment's royalty take from their licensed deals with Fox and Sony is not very lucrative (in fact in their earlier years, Marvel didn't make a dime after studio accounting), so it's not like financially this strategy is going to hurt Marvel. Their profit margins from their vertical studio business on the other hand are much higher and my guess is they can absorb a small hit to their box office numbers on their Marvel Studio films, though there's still a lot of risk with this move because of the vertical nature (higher break-even required). From a branding standpoint, Marvel still gets other studios to sink in hundreds of millions of dollars in what are essentially massive advertising campaigns for their properties, and I find it highly doubtful the other studios will purposely sink their X-Men, FF, and Spider-Man franchises just to retaliate since it's their money on the hook. Marvel's end game here would obviously to cause enough cannibalization that the other studios give the film rights back.
Or maybe I'm just reading too much into this :lol