Marvel's latest Phase 4 delays don't include Shang-Chi performing well at the box office.
Despite the MCU's recent success with its first Phase 4 movies, Disney and Marvel Studios delivered another major change to the slate that is reportedly rooted in production issues. These changes impacted almost every 2022 and 2023 MCU movie. Ant-Man and the Wasp: Quantumania moving back to July 2023. As the slate stands, Guardians of the Galaxy 3 is the only post-2021 MCU movie that wasn't delayed.
One potential factor behind Marvel's decision to not Guardians of the Galaxy Vol. 2 and this new sequel, it makes sense that Disney and Marvel don't want to prolong the gap if it could be avoided.
It also isn't surprising that Marvel Studios wants to keep Guardians of the Galaxy Vol. 3 a the May 2023 movie. This early May slot is traditionally saved for the MCU's biggest films, whether that be the Avengers franchise or similarly large events like Captain America: Civil War. Specific plot details on Gunn's trilogy capper are still heavily guarded, but he has teased in the past that Guardians of the Galaxy 3 sets up the next decade of the MCU. Will Poulter's Adam Warlock debuting here is just one example of how massive it could be for Phase 4 and beyond. It'll certainly have a massive scale to it, so it fits with what MCU fans expect from an early summer Marvel movie.
Guardians of the Galaxy 3 might even be free of the reported production concerns that Marvel has with its other projects; it is the only one of the already dated MCU movies not in production. It's possible Marvel Studios is a bit too busy for its own good with three movies filming and several other Disney+ shows gearing up. While Guardians of the Galaxy Vol. 3 is expected to begin filming later this year, Marvel doesn't appear to be concerned about it if they're confident keeping its May 2023 release date while delaying everything else.