Avengers Campus may not be canonical to the primary Marvel Cinematic Universe but can be thought of as taking place somewhere else in the vast multiverse. Meaning that it is still heavily influenced by the MCU films and shows.
Marvel Studios President Kevin Feige said, in regard to costumed heroes being present at the park, that "there are already characters of films that people haven't seen yet waiting to step around these corners of Avengers Campus." Already, attendees have seen various forms of Loki walking around the park and props related to his show.
It isn't a surprise then that more characters will slowly be introduced into Avengers Campus, starting with the Eternals.
THE ETERNALS RISE AGAIN
In an official blog for Disney Parks, Senior Communications Manager for Disney Live Entertainment, Shawn Slater, confirmed that, like Loki, characters from the upcoming Eternals film will begin populating Disney California Adventures' Avengers Campus later this fall.
Characters from Shang-Chi and the Legend of the Ten Rings and other upcoming MCU series were also teased for arrivals at some point this year.
A STORY WITH THESE COSTUMED HEROES
One of the more inventive forms of minor storytelling that Avengers Campus has done has been introducing new incarnations of Loki as the show progressed. It will be interesting to see that applied to other characters in films too.
Perhaps before their respective films are released, they appear as they do in the trailer, but after it has opened in theaters, the costumed hero in the park could have an alternate appearance. Hypothetically, if Shang-Chi gains the Ten Rings from his father in the film, he'd now be seen wearing them while traversing Avengers Campus when the film was released.
Avengers Campus really does sound like a fun location for avid fans of the franchise to visit, and it will constantly be changing as the MCU progresses.