

In Spider-Man: No Way Home, we learn that However, with the quotes from the main universe I don’t think it correlates to every universe and doesn’t appear to have done to the main one. It also shows that in that universe Strange had become the Sorcerer Supreme. This confirms that the Sorcerer Supreme is indeed a rank/leadership position. Doctor Strange Lost His Heart Instead of His Hands?” The Ancient One: Without her death, you would never have defeated Dormammu and become the Sorcerer Supreme, and the guardian of the Eye of Agamotto. The Watcher: The man of science became the Sorcerer Supreme. What If.? episode 4 has some extra information on this. Wong can still be stern and caution Strange even if he is a lower ranked because that's what mentors and more experienced people do. However, Strange is the Master of the New York Sanctum and so is more superior to Wong (under current information anyway, things may change in NWH!). He did so in Doctor Strange and has carried on doing so since. However, to answer why Wong is acting like he is in the Spider-Man: No Way Home, Wong is a mentor to Stephen. For such a big event it would have at least a mention so we can assume it hasn't happened yet. Then in all of the media Strange appears in afterwards: Thor: Ragnarok, Avengers: Infinity War and Avengers: Endgame no mention is made of Strange having become the Sorcerer Supreme. Earth has no Sorcerer Supreme to defend it. Word of the Ancient One’s death will spread through the Multiverse. Wong: You might have a gift for the mystic arts, but you still have much to learn. It is later spelled out for us at the end of the film that the Sorcerer Supreme "job" is still vacant with interviews pending. With its Master gone, it needs another, Master Strange. The Ancient One: You defended the New York Sanctum from attack. At the end of Doctor Strange he has been made Master of the New York sanctum.

Strange is yet to become the Sorcerer Supreme in the MCU.
