While the deal between Marvel and Sony that brought Peter Parker to the MCU is likely not to be something that lasts forever, based on the popularity of the character Marvel will probably want it to last as long as possible.
The fact that the Spider-Man: Homecoming sequel is the film that’s going to launch Phase 4 of the MCU shows that the character is key to Marvel’s future plans.
Still, if the door is being left open for these two worlds to tie together, this idea of obscuring Osborn to the audience could be a movie in that direction.
If we ever actually do see Spider-Man appear in the Sony movies and it’s Tom Holland in the role then it’s only going to confuse people if we end up with two different Norman Osborns.