And I dont see how they gonna get everyone aboard to star in the Avengers movie,it's gonna be a cluster fuck.
Not to mention if they ever have a big crossover from the people in the Marvel movies it's going to be almost unthinkably expensive. (Unless they already have some clause written in all the actors contracts from before that will make them do it for almost free, which they probably don't.) It would be hundreds and hundreds of millions of dollars just to pay the big time actors. It would either be that or they would have to start over with new actors in those roles.