He already exists, whether he will become in Spider-Man is something we quite don't know yet.

I feel like Sony might use Miles Morales as a bargaining chip to get Disney to integrate the SPUoMC into the MCU

I feel like they might have to cuz of chadwicks death

Does anyone know how long Sony will have the rights to Spider-Man? I hope Marvel Studios finds a way to buy back the character rights, since they can use those characters in so many different ways for the MCU.

And if Disney bought Fox (which has a much higher net worth than Sony), they could buy Sony to get the rights back like they did with Fox

They cannot (and should not) buy Sony or it could be a monopolization of entertainment. Sony has won rightfully the rights to the characters, whether we like it or not.

Sony can have the rights as long as they keep producing films in a 7 year span, if they do not do anything in 7 years, the rights go back to Marvel immediately, but that is something that is not going to happen.

I think the fact we got one Spider-Man in the MCU is miracle enough.