I notice that archaeologists seem to show increasing levels of respect to corpses based on how recently deceased they are; If a dig on a suspected Roman settlement finds the remains of a Roman villa that extends under a modern graveyard or cemetery, they shrug and say "Well there is doubtless some interesting stuff under the graveyard, but we can't dig there, so we will never know for sure"; while if the same dig encounters a 14th Century graveyard above the Roman remains, they will excavate the medieval remains too, after forensically confirming their age; and if they find a Roman mausoleum, its excavation becomes the highlight and centrepiece of their dig.
It seems that you can't dig up what is likely some living person's father; and you must be wary about digging up someone who might be identifiable as a specific living person's great18-grand father; but as long as the probability of even the most enthusiastic genealogist proving a familial link is exhausted, anything goes.
Perhaps the same is true of information about people's lives? I am not sure I want people to know exactly what my great-grandad got up to in a French brothel during WWI; but it is impersonal historical information to learn what Biggus Dickus Maximus was doing in the brothel at Herculaneum the day Mount Vesuvius went 'bang'.