Robert Downey Jr. completed his character arc as Iron Man in the Marvel Cinematic Universe in spectacular fashion. He made the ultimate sacrifice to save the universe.
But now it looks like Robert Downey Jr. may still have an Iron Man appearance left in the MCU. Reportedly, it seems Robert Downey Jr's Tony Stark, aka Iron Man, maybe back in Black Widow, according to Deadline. It's a standalone prequel about 34-year-old Scarlett Johanson's Natasha Romanoff who is trained up by the USSR to become its first Black Widow - a spy, martial arts expert and sniper. The movie reportedly takes place after the events of Captain America: Civil War.
So it is a possibility that Robert, as Iron Man could make a cameo in the Marvel movie. Robert Downey Jr. has never expressly said that he was done with the Marvel Cinematic Universe. In fact, neither has Disney or Marvel. They have never fully committed to keeping Robert out of future Marvel movies.
It is known that both Robert's Tony Stark and Scarlett's Natasha Romanoff were killed off by Thanos, played by Josh Brolin, in Avengers: Endgame. As of now, Robert Downey Jr.'s appearance in the Black Widow movie is a rumour. But we have to say that fans will be excited to see Robert Downey back as Iron Man. Disney is due to release Black Widow on May 1. Reportedly, the supporting cast includes David Harbour, Florence Pugh, Rachel Weisz, O-T Fagbenle, Ray Winstone and Olivier Richters.
Though Black Widow is a spy, she has have had quite a few interactions with superheroes as could be seen in the Avengers movies. Maybe the movie will explore her early days as well as her days as part of the Avengers. We'll just have to wait and see.