There is nothing for now that can tell for sure whether or not "Iron Man 4" will materialize. The reason, reportedly, is that Robert Downey Jr is set to appear in three movies as Tony Stark/Iron Man.
Downey Jr will be seen reprising his role in the upcoming "Spiderman: Homecoming," expected to release in July 2017. Moreover, he will also be a part of "Avengers: Infinity War," both the parts, expected to release in 2018 and 2019.
From the looks of it, "Iron Man 4" will not happen before 2020, thanks to Downey's choc-a-block movie schedule. Despite three back-to-back movies, Downey Jr is still looking forward to do the fourth "Iron Man." "I don't know how long I'll do it for. I'll keep playing Iron Man for a couple more years, I guess," the 51-year-old "Sherlock Holmes" actor told The Daily Star.
There is not much information out there regarding "Iron Man 4," but according to latest rumors, Marvel may consider casting a woman for Robert Downey Jr.'s role. In fact, the speculation says that Natasha Romanoff, aka Black Widow (Scarlett Johansson) will also be wearing an "Iron Man" suit. Even though the idea seems absurd, the storyline has a basis, as per Marvel's "Ultimate" comic book in which Tony Stark and Natasha Romanoff are a couple. This is when Stark gives a suit to Romanoff. However, their love story bombed as Romanoff becomes a conspirator, working against the Ultimates. She also kills Stark's butler, Jarvis.
