No matter how many theories fans have compiled, the Spider-Man actor himself has spoken on the largest rumor to spiderweb around the still-titleless third movie.
Tom Holland denied the involvement of Spider-Men before him, actors Andrew Garfield and Tobey Maguire, in his third Spider-Man film. Holland made his Marvel debut during Captain America: Civil War (2016), and from there, has been in a number of solo films and Avengers team-ups. Faced with the pressing question about past Peter Parkers, Holland was firm in his dismissal.
"No, no, they will not be appearing in this film," he firmly told the Esquire when questioned about the possibility of the Marvel alumni returning. "Unless they have hidden the most massive piece of information from me, which I think is too big of a secret for them to keep from me. But as of yet, no. It'll be a continuation of the Spider-Man movies that we've been making."
Garfield and Maguire have been tangled in a web of rumors that have been reported upon and denied time and time again. Holland's straightforward denial of the rumor could be Disney and Marvel's way to attempt to shut down any further questions in order to protect the "big reveal." It's been known that Holland has had trouble keeping confidential information, well, confidential in the past, and this could be Marvel's tactic to preserve the surprise.
Confirmed or not, Spider-Man 3's potential cast is teasing a live-action Spider-Verse crossover, and Marvel could expand their multiverse as the studio's next phase plans to pack a punch. Spider-Man 3 swings onto big screens on December 17, 2021.