Doctor Strange Director Quit due to PG-13 Demands from Marvel Studios?

Recently we found out that Dr. Strange in the Multiverse of Madness, a follow up to the original Dr. Strange lost its director Scott Derrickson. At that time, There are a lot of rumors, that constantly pop up that Scott Derrickson quit because Disney did not agree with the movie to be R-Rated. Instead, they wanted it to be PG-13.

That's a joke. There were never any mentions by Marvel Studios. As a matter of fact, The only place I've been able to locate such things is through social media. 

As far back as I have actually been able to look into, which is right after the original release of Dr. Strange i.e. when they started talking about a potential sequel. The only thing that's ever been sort of a through-line was taking a darker approach to the sequel. By having the Nightmare as a villain.
But It's never explicitly stated that it's R-Rated and if we just look at R-Rated and PG-13 films out there. There is horror done on both of these levels.
Now If we go back and think about the director quit scene because they wouldn't let him make an R-Rated film. Let me ask you this question, Why would he stay on and be working on this film since 2016 for four years of his life? If he knew they weren't gonna, Let him make an R-Rated film. 

At one time it was heavily rumored that Black Widow could be R-Rated. People were convinced, It could be again. There is no reason to alienate an audience: That's expecting a pg-13 movie by making an R-Rated specifically in a trilogy. It just doesn't make sense from Disney's point of view.