The Marvel Cinematic Universe is at its biggest crossroads since its launch with the original Iron Man 11 years ago. April's Avengers: Endgame has repeatedly been promised as the culmination of the story told across the preceding 21 films. But the film that actually stands as the most likely to set the tone for the brave, new MCU moving forward is actually Captain Marvel, coming out well over a month before Endgame.
Expectations are riding high for Captain Marvel, significantly more than the usual financial obligations involved with maintaining the success and visibility of the MCU cinematic brand overall. From a logistical standpoint, the MCU is going to need a new flagship superhero after Endgame. Most of the original Phase One actors' contracts come to an end with the fourth Avengers film, with several actors either publicly expressing their plans not to reprise their roles or aging out of their cinematic superhero careers. While the MCU post-Phase Three will feature plenty of familiar faces, at least initially, its flagship heroes in Iron Man and Captain America are likely moving on.
Brie Larson's Captain Marvel is actively being positioned to become the biggest superhero coming out of her debut origin film, and is largely implied to be pivotal in defeating Thanos and undoing the tragic ending of Avengers: Infinity War. It's no grand coincidence that her debut will be the MCU film immediately leading into Endgame. While Black Panther and Doctor Strange will both continue to be important franchises for the MCU, both characters met their temporary demise in Infinity War, with Carol Danvers now presumably leading the charge to resurrect them. This will inevitably inform the MCU beyond Avengers: Endgame.
Described by Marvel Studios President Kevin Feige as "the new face and leader of the Marvel Cinematic Universe," the MCU is slated to become a much more diverse place after Phase Three. While Feige has remained largely tight-lipped about the post-Endgame MCU, he has revealed that the studio is actively building a cinematic universe where over half its superheroes will be women. A solo Black Widow film is reportedly in development, as is an Eternals film that features cosmic female members. The most visible superhero in this new direction for the studio will be Larson's Carol Danvers.