It is far from uncommon for rewrites or reshoots to occur throughout production on any given film. That includes Doctor Strange in the Multiverse of Madness, which, evidently went through a multitude of changes throughout filming. Virtually everything apparently changed, with the exception of a single facet.
Discussing the film with co-star Elizabeth Olsen for LADbible TV, Cumberbatch touched on how reserved Marvel Studios was when it came to lettings the film's stars know what was coming and what they were filming. During the talk, he said, "The only thing that didn't change during the filming of this film was the title."
Multiverse of Madness brought a number of storylines to their climax and to their apparent end, including the arcs of Doctor Strange and Scarlet Witch, though that does not mean their stories are over. Cumberbatch himself previously stated that he would be willing to continue playing the Master of the Mystic Arts for the next decade, provided there was an powerful enough story ahead. In an interview, the actor stated, "If they keep me, and it, interesting and keep him evolving and try to exercise his full potential as a character, I think there’s a lot of places for him to explore. So yeah, bring it on."
The Marvel Cinematic Universe does appear to have big plans for the former Sorcerer Supreme, as evidenced by the recently released film's post-credits scene, introducing Clea. Writer Michael Waldron said the character was someone they had wanted to introduce for some time already, though they needed to conclude Strange's current love story first. Teasing the potential of Clear's character, Waldron said, "Her backstory is fascinating. She's the niece of Dormammu, the giant floating head from the first movie. And so, they have a lot of great adventures in the comics, and we knew we wanted to introduce her, but it felt like we had to close the book to some extent on his love story with Christine Palmer."
Meanwhile, Olsen recently discussed Scarlet Witch's future in the MCU, admitting that she does not know what lies ahead, if anything, only that the arc she began eight years ago in Avengers: Age of Ultron needed to come to an end. "I am [satisfied]," she said. "I think somehow it needed to end where it ends at some point, and I’m curious about where we go from there."
Doctor Strange in the Multiverse of Madness is playing in theaters now.