Hi hi hello, educator of archivists here. I have this discussion when I teach digital curation and collections, because archives-style consent processes break down at social-media scale.
One thing I do try to impress upon students is NO MEANS NO unless there's an overriding public stake (e.g. for a politician).
Then I tell them THE FEDI SAID NO, do what's right and leave people the hell alone.
Because no still means no.
A lot of people don't want this, though. They want to exercise their right to be forgotten. Or they want to enjoy the ephemerality of temporary posts. They don't want their data stored in a system they don't have direct control of.