Miles's new Spider-People friends return to their own realities, but that doesn't mean he can't still communicate with them between dimensions.
We know that Gwen and Miles can chat and we imagine that'll lead to them reuniting in the flesh in the sequel, The plot is set to focus on the pair, although chances are that if it's another multiversal story, it will also feature some other Spider-Men and Women.
We already have Spider-Ham, Spider-Man Noir, Penni Parker and the older Peter Parker voiced by Jake Johnson, as well as Oscar Isaac's Spider-Man 2099. However, there are plenty of other Spider-People to choose from.