Sure, he's obligated to maintain certain things to go along with the overall storyline that's being told in the cinematic universe. But it could easily be said

Sure, he's obligated to maintain certain things to go along with the overall storyline that's being told in the cinematic universe. But it could easily be said he has to follow guidelines about any project he would work on that has studios with other people in charge involved. Unless he wishes to fully fund the project himself.