In a report from Vanity Fair on the secrets of the Marvel Universe, it was stated that all of the contracts of the original Avengers actor’s end after Avengers 4 in 2019.
As reported in the article :
“After Avengers 4, an ambitious multi-franchise crossover movie slated for release in 2019, at least some of the original characters who sit at the center of the billion-dollar Avengers team will be hanging up their capes and shields. That’s partially because the Marvel contracts with the actors who play them—Evans (Captain America), Ruffalo (Hulk), Downey (Iron Man), Johansson (Black Widow), Hemsworth (Thor), and Renner (Hawkeye)—are coming to an end.“
For many, Avengers 4 will be their swan song, and after which they will finally end their superheroics. There is a chance some actors will renew their contracts, as talks of new movies have been discussed, including a Thor sequel and a Black Widow solo movie.
But if it is the end, the stars are definitely going out as a team, based on a quote from Chris Hemsworth on the actors being together:
“I thought, Could somebody take a photo of this? We’re all aware that this is going to be the last time we get to hang out like this.”
Avengers: Infinity War hits theaters May 4, 2018.