Corrected entry: The point of the whole multiverse accident is that anyone who knows "Peter Parker is Spider-Man" gets pulled into this world. However, this does not apply to Tom Hardy's Venom at all (post-credit scene): not only does he not know who Peter Parker is, but he also doesn't even know who Spider-Man is. Him being one of those being transported into the same universe does not make any sense whatsoever.
Corrected entry: The whole "make everyone forget Peter is Spider-Man" spell is a massive plot hole: it is understood the spell works simply by making people forget Peter Parker. In no way is it implied it actually alters reality. Even if people forget Peter Parker, there still is a record of him being Spider-Man in TV shows, news broadcasts, papers, magazines, online videos, documents, police records, news records... There is no explanation given as to how exactly that spell eliminates those too.
Correction: The new extended edition reveals that Peter's face is obscured in photographs. It's obvious that any dead giveaways have been altered by the spell.
Correction: It's magic. If everyone is to forget who Spider-Man is, then yes, reality has to be altered to remove his identity from all those things you mention. It has to, or else it won't work. Because of this reality altering ability, tampering with it causes reality to come apart, hence the plot of the movie. Not a plot hole, but the plot.
Correction: The post-credits scene from Venom: Let There Be Carnage suggests that the Symbiotes are a hive mind across the multiverse. Since the version of Venom from Spider-Man 3 knows Spider-Man's secret identity, this would extend to all other Venoms across the multiverse, whether they are aware of it or not.
Phaneron ★
That actually makes sense.
Epigenis