Mark is just being his honest, truthful, mirthful self. He’s got zero ego and a huge sense of humor. He engages in a lot of harmless trollish fun but to categorize him as having anyone ‘over a barrel’ is ludicrous. I suspect ruining a movie for anyone would be the last thing someone as appreciative of this series legacy as he is would do.
Maybe he’s playing up his differences with some of the choices and the whole diva thing for fun but that’s because he’s a master at hype.