Marvel Studios Executive Stephen Broussard has addressed rumors surrounding the possible return of Robert Downey Jr. and Chris Evans in Avengers: Secret Wars. Broussard hinted that RDJ's return may not be happening due to the introduction of new characters in upcoming projects, such as Cassie Lang in Quantumania, Kate Bishop in Hawkeye, and Jack in Werewolf by Night. He explained that after the first 10 years of Marvel storytelling, the torch is being passed on to a new generation of heroes, and it's time for new characters to step to the forefront. He refers that this approach is in line with what has always happened in the comics. Stephen Broussard emphasized the importance of introducing new characters to the Marvel Cinematic Universe (MCU) in Phase 4 while speaking to io9. Broussard stated that Phase 4 is all about bringing in new characters and telling their stories. He noted that now that these new characters are on the board and there is a big villain coming in the form of Kang the Conqueror, it is about exploring what these characters will do with their newfound power.
Broussard compared the situation to the famous Spider-Man quote, "With great power comes great responsibility." He hinted that the upcoming films will explore how the new characters will use their power and the consequences that come with it.
While fans may have hoped for the return of popular characters like Iron Man and Captain America, it appears that Marvel is looking to the future of their cinematic universe. With new characters comes the opportunity for new stories and more diverse representation within the franchise, which is an exciting prospect for fans. This approach also allows for more diversity and representation within the franchise. Thus, it seems that Robert Downey Jr.'s tenure as Iron Man has come to an end as Marvel is looking toward the future.