Marvel's Phase 4 is going to be densely packed, with the first two years seeing 10 titles released in rapid succession. The reason so many titles will come so fast is because, for the first time, Marvel won't be confined to the movie theaters. Instead, five of the new projects will be limited TV series airing on the new Disney+ streaming service, featuring actors from the big screen franchise as the title characters. However, as this theory about Scarlet Witch in WandaVision shows, this will be a complex undertaking.
When Marvel launched Phase 2 in 2013, it was riding high on the success of 2012's The Avengers, which was the highest-grossing film ever at the time. It created the "Marvel TV" division, and Agents of S.H.I.E.L.D. for Disney's ABC network. Starring Clark Gregg, who has played Phil Coulson since 2008's Iron Man, the series attempted to tie the series in with the franchise on the big screen.
It failed. Screenwriter Joss Whedon refused to play along, and friction developed quickly. But one cannot take a 22-episode series that runs September to May and have it gracefully tie in to three movies a year, which come at odd times in the network schedule.
That's where WandaVision and Disney+ come in. During the San Diego Comic-Con presentation, actress Elizabeth Olsen revealed the spring 2021 release date was so the limited series could lead into Doctor Strange in the Multiverse of Madness on May 7, 2021.
But how exactly does that work? One theory suggests WandaVision could be basing itself off the "House of M" comic, where the character rewrites time. Wanda Maximoff, aka the Scarlet Witch, is one of the most powerful figures in the Marvel Cinematic Universe. Infinity War touched on it when Okoye asked why she wasn't on the battlefield from the beginning, but it hasn't been explored much.
It would also explain the discrepancy between reports WandaVision is set in the 1950s and post-Avengers: Endgame, when Vision is dead. If both are true, then Wanda may be trying to rewrite time to bring Vision back, hiding him in a spot out of time.
One Redditor, u/hiero_, suggests that the inability to deal with reality drives her over the edge.
Wanda goes to the past with Vision and builds the life she wanted with him from scratch. It's pitched as a psychological thriller as Wanda slowly descends into insanity throughout the story. In the comics, this story arc ends with the twist that Wanda fabricated an illusion for herself all along and none of it was real.
In her grief, Wanda then shatters the timeline into millions of multiverses, which would make her the antagonist for Dr. Strange's sequel. But her actions could also lead to a long-awaited development in the MCU:
Wanda loses her mind and changes reality. Doctor Strange is the only one who can stop/save her. Mutants are created as a result.
In the comics, Wanda was an X-Men character. The MCU had to alter her backstory to bring her into the franchise. Having her "create" mutants would be a perfect way to correct the MCU. It would put her back where she belongs, and introduce the X-Men into the MCU all at the same time.