In the lead-up to the release of Spider-Man: No Way Home (whose title was finally revealed) fan theories continue to circulate the internet in anticipation of the new Marvel film. With the recent introduction of the multiverse into the Spider-Man franchise via Spider-Man: Into the Spiderverse, there are endless narrative possibilities for the new film to explore.
In 2019, Avengers Endgame saw the death (or in one case, significant aging) of multiple characters including Chris Evans's Captain America, Robert Downey Jr.'s Iron Man, and Scarlett Johansson's Black Widow. The lasting repercussions of Thanos's reign signaled the end of the original Avengers franchise, making way for a new generation of Avengers to take its place. However, the MCU is notoriously sneaky, leaving room for constant fan speculation surrounding any "definite" consequences or storylines. As a result, the exploration of multiple different universes in Spider-Man: Into the Spiderverse allows for a potential crossover in the new Spider-Man film.
In a recent interview with current Spider-Man Tom Holland, the British actor called Spider-Man 3 "the most ambitious standalone superhero movie ever made," continuing to allude to the film's endless potential. There are also multiple reports of Marvel characters frequenting the Spider-Man 3 set including WandaVision's Elizabeth Olsen, and Daredevil's Charlie Coxx. Due to these reports, some fans have begun to speculate whether the film may be an opportunity to reunite the original Avengers. Perhaps in another multiverse there exists an Iron-Man and Black Widow who survive Endgame, and who can therefore re-enter the franchise through the Spider-Man multiverse.
However, this possibility seems unlikely considering Doctor Strange's prognosis of the Avengers' future in Avengers: Endgame. Prior to the final battle with Thanos, Iron Man consults Strange about the likelihood of the Avengers defeating Thanos and restoring the universe to its rightful state. In response, Strange states that there are 14,000,605 potential outcomes of the battle, only one of which sees the Avengers emerge as the victors. Therefore, it seems unlikely that the multiverse could be manipulated in Spider-Man 3 to reunite the original team.
Moreover, it's doubtful that many MCU fans would even want said reunion, as the ending of Avengers: Endgame, while leaving audience members teary-eyed, also managed to satisfy ardent fans of the franchise. If Marvel were to use Spider-Man 3 as a vehicle to reunite the original Avengers, they may risk frustrating fans of Endgame and diluting the stakes of the Marvel Cinematic Universe as a whole. Audiences were able to follow these characters for years, and got to see their stories come to an end, as all stories do. It would almost be unfair to re-write the history of Steve Rogers and Tony Stark just to bring them back into the fold.
Another issue is that these movies are being made in the real world and not on a comic book page. Downey and Evans have both been vocal about wanting to move on from their roles in the MCU now that they have reached their logical conclusions. It's a fair point, as both of them are accomplished actors who now have the time to do projects that don't involve them playing the same superheroes for years on end.
On the other hand, the success of WandaVision reflects how the multiverse can successfully be harnessed to re-integrate characters into the Marvel franchise. Since the start of the series, fan theories have circulated speculating that the show will introduce new characters into the Marvel Cinematic Universe. Episode 7 of the pseudo- sitcom featured its most explicit allusion to other continuities of the MCU yet, when the program was "interrupted" by a commercial for an anti-depressant named Nexus. In the commercial, Nexus promises to "anchor" the user of the drug back to their reality. In the X-Men comics, the Nexus of All Realities refers to a significant cosmic artifact called the M'Kraan Crystal. This allusion left fans believing that the series will soon re-integrate the X-Men into the MCU, and serves as an example from which Spider-Man: No Way Home writers can potentially draw inspiration.
Perhaps, Marvel will even harness the building anticipation for Spider-Man: No Way Home, and the continuous intrigue of WandaVision, to set the stage for the epic Avengers versus X-Men comic saga. Ultimately, the plot details of Spider-Man: No Way Home are largely unknown at this point. Only time will tell what the future of the MCU has in store.