Ever since the announcement of Spider-Man's inclusion in the Marvel Cinematic Universe, two major debates have been circulating like mad. The first of which has to do with casting, but it's the second one that I'm concerned about. When Spidey finally makes his Marvel debut, will he continue as Peter Parker, or will the studios take a fresh turn with Miles Morales?
I'm not suggesting that they team up and for some kind of web-slinging duo (although that would certainly be interesting). There is a way that both wall-crawlers could be handled well, but one at a time.
I am completely convinced that Miles Morales would be a perfect addition to the MCU, but fans of Peter Parker haven't had the chance to say goodbye yet. Like it or not, Parker has claimed the title of friendly neighborhood Spider-Man since 2002. That means he has retained that title for thirteen years. I imagine more than a few fans would be upset if you just replaced Parker out of the blue.
What I suggest is that in [Captain America: Civil War](movie:994409), or whenever Spidey is introduced, you start off with Peter Parker. Regarding casting, I'm up for Dylan O'Brian, but don't offer him some long contract or anything. Give him a two or three movie deal and start searching for someone to play Morales, you're going to need him soon. Let Parker get re-introduced to the fans, but in a stand-alone Spidey film, introduce Morales.
While Parker is swinging around, fighting off whoever the next villain ends up being (Mysterio or Kraven please), have Morales tour Oscorp and have a radioactive spider crawl into his backpack. When Morales gets back home, probably at the very end of the film, have him get bitten. That would be a pretty good cliffhanger if you ask me.
When Spidey returns for [The Avengers: Infinity War](movie:738027), I hate to say it, but kill him. Give him a dramatic death at the hands of Thanos (or maybe Loki, that would be interesting). That way, after Earth's mightiest heroes and the Guardians of the Galaxy vanquish Thanos once and for all, the audience will have to mourn one of the most popular heroes in the history of comic books themselves. This way the audience will finally have closure on the character.
In a post-credits scene, show the silhouette of yet another web-slinger, and wait for the next Spidey movie.
In the next stand alone Spider-Man, start off with Miles Morales swinging through New York with a makeshift Spidey suit, maybe attempting to halt a street thug or two. While New York mourns the loss of a hero, have Morales learn to control his powers. Distraught that he wasn't there to help Peter Parker before his death, have Miles adopt the "with great power comes great possibility" mantra, much as the character does in the comics. His attempts to fight crime draw the attention of S.H.I.E.L.D. and they introduce him to [The Avengers](movie:9040).
This way, Peter Parker could still be a part of the MCU, and the studios could still play with Morales' abilities, like his camouflage and [Venom](movie:372411) strike abilities. Not to mention the MCU will finally have that diversity that fans are clamoring about.