1) Miles Morales Exists
Even better than the tease of future supervillains is the hint that there’s another Spider-Man out there in the MCU besides Peter Parker.
When Spidey tries (and totally fails) to interrogate Aaron Davis (as played by Donald Glover), he ends up convincing the guy to tell him where Vulture’s gang are. Aaron admits that he doesn’t want Toomes’ dangerous tech in the neighborhood as he has a nephew who lives locally. Cue Marvel fans’ jaws hitting the floor.
You see, in the comics, Aaron Davis is the Prowler, a cat burglar who happens to be the uncle of Miles Morales, Peter Parker’s successor as Spider-Man in the Ultimate universe. Though his near-namedrop could simply have been an easter egg for the fans, and not a promise that Miles will actually appear, the implications of it are massive nonetheless.
We now know that Miles exists in the MCU, which leaves the door open for his introduction at some point in the future. Seeing as Tom Holland is contracted for six movies, Peter Parker likely won’t be going anywhere for a while, but that doesn’t mean Miles is off the cards. Miles and Peter could be around the same age in this universe, too, which could lead to a kind of buddy cop Spider-Man movie, where the two team up. Hey, we can always dream, right?