We don't know what will happen to the Sorcerer Supreme in Avengers 4, but fans are now talking after the Doctor Strange director posted something interesting to Twitter. The image is a panel from an old Marvel comic and fans are now speculating that it might connect to whatever Scott Derickson may be planning for Doctor Strange 2.
The image itself doesn't show much, just a lot of exploding cosmic energy and the words "I choose the good," though they are then followed by Scott Derrickson's own comment "until I don't." Since the image is regarding Doctor Strange, people are, of course, curious what the context is supposed to be. Although, the director isn't talking so we can't know for sure.
The comic panel itself comes from What If? #18 from 1977. The book was a series of usually one-off stories that imagined scenarios for various Marvel characters that were different from the normal continuity, In this book, Doctor Strange actually becomes a disciple of Dormammu. This particular sequence sees Dormmamu taking on Eternity, and Doctor Strange finally choosing the side of good rather than the side of evil.
Naturally, since there's a strong expectation that we'll be seeing a Doctor Strange 2 sometime after Avengers 4, fans are wondering if Scott Derrickson is giving us a hint as to what the next movie will be about. Of course, with the comic panel and the director's own comments being somewhat in opposition to each other it's difficult to guess what he would be trying to say. Could a Doctor Strange 2 see the Sorcerer Supreme got to the dark side? Or is this a hint that Eternity will be part of the new movie? Will Dormammu be back even though he previously agreed to leave Earth alone? There's a number of different directions we could take this if we want to try and speculate, but there's certainly no clear meaning meant.
Of course, it's equally, if not more likely, that Scott Derrickson is just making some vague comments about his own life, and simply using a Doctor Strange comic to illustrate his feelings because of his personal connection to the material. He probably has a lot of Doctor Strange comics around as part of his research into the character when making the first movie.
There probably will be a Doctor Strange 2, though when we might see it is unknown. We clearly won't be getting many details about Phase 4 of the MCU until after Avengers 4 and with Guardians of the Galaxy Vol. 3 on hold following the removal of James Gunn, who was also working closely with Marvel on the entire new phase, it's possible that things are currently being reworked anyway, which could either move up, or push back, a future solo movie for Doctor Strange.