"I think it's been long enough, it's been more than a decade since her passing"

Would you be happy dying with the knowledge that a decade later your private info would be fair game? If the answer is no then I think that's a good case for why it shouldn't matter how long it's been since someone's death in terms of when it's okay to reveal private info about them.

No. But it doesn't matter if it's Diana or anyone else, and I see no reason for it to matter that she's dead, it's just a matter of privacy. I think that everyone should have a right to privacy in these sort of matters, regardless of their standing. If they're dead you could make the 'what do they care' argument, but I think that the fact they wouldn't have wanted private info to go public should still be respected. Also, I don't want to die knowing that private info about me might be released after a while.