If previous rumors were any indication, Robert Downey Jr. was not doing "Iron Man 4" at all due to limited budget. Needless to say, Downey is the highest-paid actor on Marvel Comic Universe's roster right now, and even though he sort of guarantees box-office success, rumors indicate that the executives are not considering another big budget movie focusing only on Tony Stark. The concern is not only the high price tag that comes with the star we all know as RDJ, he may also be too old for his role, by the time film even starts.

If the fans were to go by the comic books, Tony Stark has already passed on his legacy to a young successor, Riri Williams. This 15-year old prodigy is the next one to man the Iron Man suit. However, it has already been reported that Stark's successor will be called "Iron Heart."

Based on this news, the speculations started brewing that perhaps Tony Stark's days in MCU may be numbered. In fact, some even say that Stark's role might end in the next movie, "Spider-Man: Homecoming" where he will appear alongside the new Peter Parker.

Now, the rumor says that should there ever be an "Iron Man 4," RDJ may not reprise his role as the famous Tony Stark. Even though most fans were very disappointed to learn about the current events and possibilities, some support Marvel and MCU nevertheless.