Kevin Feige talked about the reason behind the survivors of the original Avengers superhero from annihilation by Thanos in Infinity War. At the end of the Avengers story: Infinity War indeed leaves more old champions, such as Iron Man, Thor, Captain America, Hulk, and Black Widow.
According to the boss of Marvel Studios, it's no coincidence that the original Avengers superheroes were saved. Marvel wants the original superheroes to become the main focus of the story climax that was built over the past 10 years.
"I think, for the film series that has been running for 10 years and heading to the conclusion with Avengers 4 later, which you don't usually find in these kinds of movies, you are like doing math (doing calculations). Then realize, the Avengers aslilah are left , "Kevin said to io9, quoted from Comicbook.com.
Even if you don't talk bluntly about Marvel's plan for the original superheroes in the upcoming Avengers 4, it's clear, if the studio wants to make Iron Man and friends who are the founders of the Avengers say goodbye well. These original superheroes, like Chris Hemsworth, Chris Evans, and Robert Downey Jr., have already admitted Avengers 4 will be the end of the contract with Marvel Studio.
Despite eliminating other superheroes, fans believe, the death in Infinity War is not eternal. Moreover, a number of champions, such as the Black Panther, Spider-Man, and Guardians of the Galaxy have been confirmed to be returning with their respective solo sequels.
Avengers 4 hasn't announced other leaks. The film is planned to air in the early summer of 2019.