Rumors are swirling that Oscar Isaac might reprise his role as Moon Knight in the upcoming Avengers: Doomsday. The speculation gained traction after Isaac unexpectedly pulled out of Star Wars Celebration in Japan due to changes in his production schedule. Originally set to attend, his absence sparked curiosity among fans, especially given that Avengers: Doomsday is currently in production in London.

Isaac's withdrawal from Star Wars Celebration was announced on the event's official social media, following a much-anticipated reveal back in February about his potential return as Poe Dameron. The change in plans led fans to connect the dots, with many speculating on social media about Isaac joining the cast of Avengers: Doomsday.

While the theory is intriguing, it remains unconfirmed. Marvel has a penchant for surprises, yet Isaac was notably absent from the initial cast announcement for Doomsday. However, Marvel Studios producer Kevin Feige hinted that not all cast members were revealed during the livestream, leaving room for speculation. "We revealed many, not all," Feige stated during a video call at CinemaCon.

Isaac previously starred as Moon Knight in a six-episode series released in 2022, but no sequel has been officially announced. Avengers: Doomsday is slated to premiere on May 1, 2026, promising a star-studded lineup of returning heroes and new faces.

In other MCU news, fans are buzzing over Robert Downey Jr.'s recent Doctor Doom-themed birthday invitation, adding another layer of intrigue to the unfolding Marvel saga.

The cast reveal for Avengers: Doomsday last month spotlighted several veteran X-Men actors, including Kelsey Grammer (Beast), Patrick Stewart (Charles Xavier/Professor X), Ian McKellen (Magneto), Alan Cumming (Nightcrawler), Rebecca Romijn (Mystique), and James Marsden (Cyclops). This heavy inclusion of X-Men characters has led fans to wonder if Avengers: Doomsday might secretly be an Avengers vs. X-Men movie.