How much can a story rely on outside information/pop culture osmosis to work?

I had this thought concerning something I recall from Insomniac Spider-Man 2, spoilers for the Mysterio quest

The whole deal is that Mysterio has supposedly gone straight, cleaned up his criminal ways and opened a legitimate business, with the dangling mystery of “but is he?”

Putting aside that reveal of who actually is behind it is really cheap (if you listen to the audio logs it’s really not at all implied it’s actually that person), the issue I have is that it all hinges on you the audience caring that one of Spider-Man’s rogues has turned over a new leaf and become a good guy. Cue the canned awws.

He’s the problem: we don’t know this version of Mysterio, because he wasn’t in either of the previous two games and was maybe in a single offhand mention in one of the backpacks from the first game. Not to mention that this side quest isn’t with Peter, his longtime foe, but Miles, a guy who’s literally never met Mysterio before this so there’s no history or connection.

It is definitely the case they are relying on you just knowing who Mysterio is as a character in pop culture and letting that fill in the blanks and be the emotional crux.

So my question is: how much of that can you use? Because I can think of an example in another game that used this explicitly from the writers, and that’s Sephiroth in FF7 Remake, because according to the directors they felt that he’s just so well known that they didn’t need to establish him or anything since everyone already knows. Except there’s several accounts of people wondering what the fuck his deal is because they have a limited exposure to FF7 and are just kind of dropped in cold. I actually had to explain to a friend what the deal was when he played Remake because he had never played the original or seen Advent Children because he thought Remake was just gonna be straightforward.