Leaks say that Secret Wars will be a massive Endgame-like conclusion to the Multiverse Saga. Marvel might feature all sorts of superheroes joining the Avengers in their fight against Kang. It wouldn’t just be Iron Man coming back from the dead. Other dead or retired characters might appear in the film. Think Black Widow (Scarlett Johansson) and Steve Rogers (Chris Evans). And we could see superheroes from Fox’s X-Men universe and Sony’s Sony’s Spider-Man Universe (SSU). Also, rumors say that Spider-Verse characters could appear in the movie.
I’ve already explained there are multiple avenues to bring Tony Stark back. The simplest one is grabbing the superhero from the past, maybe right before he died in Endgame. The Avengers would still put him back by the end of Secret Invasion so that he could fulfill his destiny. Another equally exciting concept is Marvel introducing a Tony Stark similar to the one we’ve grown to love, but different. A variant from the multiverse that might have a bone to pick with the Avengers. That’s where Iron Man 4 would come in.