The co-writer of 2016's Doctor Strange, C. Robert Cargill has expanded on the reason why Scott Derrickson and Marvel parted ways on Doctor Strange 2.
Cargill discussed Derrickson, who directed the first Doctor Strange, stepped away from Doctor Strange in the Multiverse of Madness with CinemaBlend (via, IGN) while talking about his new book Day Zero. He confirmed that there were "creative differences" between Derrickson and Marvel, with the filmmaker wanting to do one version of the movie and the studio wanting to do another.
Cargill continued: "So he sat there and said, 'Well s***, I've got this great script that I wrote with Cargill, and I'm really proud of.' We were actually going to go out to other directors for The Black Phone."
Regarding The Black Phone, Derrickson had asked if Cargill was willing to wait until after he was done with Doctor Strange 2 to direct an adaptation. During that time, Derrickson and Marvel couldn't reach an agreement and Derrickson left the production.
"It came down to Scott," Cargill said, "and Scott’s like, ‘Well, I can make this movie that I’m compromising what I wanted to do on, or I could make The Black Phone,’ and he goes, ‘You know, I want to make a movie with Cargill. I’m gonna go make The Black Phone.’ It was, as he said publically, it was a hard choice to leave Strange behind,"
In 2020, Derrickson officially stepped away from Doctor Strange 2, and not long after Sam Rami was confirmed to be involved with the production. Benedict Cumberbatch has detailed what it's been like working with Rami.
While the sequel film isn't due to arrive until next year, it has been confirmed that the Disney Plus show WandaVision will directly set the film up. Doctor Strange 2 is only one of the projects that is a part of Marvel's Phase 4.