It may make sense, to say the least, considering that by 2020, it is already the Marvel superheroes and their respective alter-egos whom fans have associated with instead of the actors playing them. That could also be the same strategy that may be employed by Marvel Studios in the future.
While there have been reports that a fourth “Iron Man” movie may already be in the works at this time, it was actually Robert Downey Jr. who confirmed during a guesting at The Ellen Degeneres Show late in 2014 that there is no “Iron Man 4” in the pipeline and that he would be the first to announce it in public if the movie is given the green light.
Eventually, there came out rumors saying that Downey Jr. will no longer be reprising his role as Tony Stark and Iron Man in “Iron Man 4,” which critics really find odd since Marvel Studios actually put back the actor to the Hollywood A-lister club with the “Iron Man” franchise.
The “Iron Man” movies made Downey Jr. the highest-paid Hollywood actor for three consecutive years so it would really be a no-brainer for the actor to turn down the offer if ever there is one.