just want to avoid disappointing people who will want to visit something and there is nothing there. I would see it as marking all of them as "Status unknown" until somebody checks if the site still exist. I will do my best to visit if in the area.
Players are not delicate flowers, they can handle some uncertainty. Especially if it's a known thing that sometimes, POIs disappear. It also means players who find nothing where there was something before can now report that, instead of just looking around. It's another sort of discovery. That's how I would react to that, at least.
As for the "status unknown", in principle most "planetary features" are always "status unknown" unless there is someone watching at that moment. Lots of things have been changed, this is known.