I think once Spider-Verse is out people are probably going to be more open to the idea of multiple Spider-Men (or Women!) existing in movies. I'd be okay with Sony having their own Spider-Man.
I think Miles is going to be designated for CG films, but that could change. It would get kind of messy, lore wise, if Spider-people (plural) just start popping up in the same place with the same sort of origins.
Spider-verse though, that gives them a conceit that allows for there to be a lot of different spider-people in their own worlds who can then interact.
I wonder if Sony's longer term plan ends up introducing a lot of characters through their own realities, only to have a crisis like event that brings a lot of them together into one universe.
Sony and Marvel have attempted to avoid stepping on each others toes when it comes to character use. I doubt Sony will piss on Marvel after one hit, since Spider-Man in the MCU is a huge part of what gives them synergy for their pwn projects. Even though they can, I doubt that Sony is going to seperate their live action stuff that is at present soft connected to the MCU, but we can easily see them have some live action that takes place in another reality.
One things for sure, I don't think Feige is terribly impressed at the notion that Tom Holland could go from THE Spider-Man to A Spider-Man. Not that Sony wants to explicitly divide their live action stuff from Tom Holland's Spider-Man. With Spider-verse, everything from Riami Spidey to Garfield's technically 'counts', and that's just the tip of the icebergs for its implications.
But the negotiations for the new deal are going to be changing everything or nothing so we'll see.