If the studio decided that Creed 2 needed to hit a certain release date for financial reasons, and Ryan Coogler was still tied up with other things, there is not much he could have done to remain director.
But Ryan Coogler’s comments to Variety’s Playback Podcast seem to indicate that scheduling was the determining factor in him not returning.
While no one would have objected to Ryan Coogler returning for Creed 2, he has already done his part in re-launching the franchise, and now he gets to turn it over to another new voice who just happens to be a friend of his.
It sounds like Creed was a hugely emotional film for the young director, so it’s understandable that he may have been hesitant to return or feels that he said all he has to say with the first film.