2. Hawkeye, Ant-Man, Korg and Valkyrie will return
Poor Hawkeye and Ant-Man were not in the film even though many fans had hoped that it was just a way to fool fans and they will appear in the film. Well, they did not. Avengers: Infinity War revealed that they have made some sort of deal with the authorities following the Civil War and are under house arrest. Ant-Man and the Wasp will hit theatres this July and is certainly set before Infinity War since the trailer of the film did not hint at half of the life-forms in the universe being dead.
I have seen the movie twice, but I have probably missed when there is a mention of half of Asgardians dead, instead of all. I was sure that I heard that Thanos and the Black Order have slaughtered everyone on the spaceship that left at the end of Thor: Ragnarok. If I misheard, then maybe Korg (Revolution!) and Valkyrie are alive and may return in Avengers 4.
3. It would have time-travel
One other way the dead superheroes may return is time-travel. Without the Time Stone. How? We don’t know yet. There was a great talk of the significance of the subatomic quantum realm that was briefly explored in Ant-Man. Michelle Pfeiffer will star as the original Wasp who was lost in that mystical realm. Perhaps that realm can be harnessed to revert things somehow since space and time are irrelevant there.
The reason we can say for sure time-travel will be there in Avengers 4 are a few set photos. They showed the original Avengers and Ant-Man. Avengers were in their appearances from 2012’s The Avengers – Thor with long hair, Cap in original costume, Tony Stark, Mark Ruffalo in CGI suit, and so on. The odd one out is Ant-Man.
4. Captain Marvel will help the Avengers
The post-credits scene of Avengers: Infinity War had Nicky Fury sending a message to Captain Marvel before he and Maria Hill poofed out. Captain Marvel has been teased by Kevin Feige as the strongest superhero yet in MCU. It would be a relatively new iteration, Carol Danvers, which will be portrayed by Brie Larson. Larson will also appear in her standalone movie scheduled to be released on March 6, roughly a month before Avengers 4.
It would be Captain Marvel probably who turns the tables on Thanos. But where was she all along? Where was she when New York was attacked by Loki and the Chitauri army in The Avengers, or when Ultron wreaked havoc in Age of Ultron? There must be an explanation. She has been associated with the Kree race of aliens in the promotional material and seems to be a human-Kree hybrid. So likely she was somewhere in outer-space. The standalone movie, however, is set in the 1990s so it would perhaps be an origin story. Characters like Nick Fury (without eyepatch) and Kronan the Accuser will return.
Avengers 4 will release on May 3, 2019.