A few months after my grandmother died, there were a few of her belongings left at my parents' house, including a simple painting of a farm. 'We tried to see if it was worth something', my dad said. 'And it was about sixty euro's', I immediately replied. 'Yeah! Yeah, it was!', he said, surprised, as if he had no idea how I spent my time in the preceding fifteen years. He naturally was also a little bit disappointed with the painting's value. It had hung so long in my grandmother's house that the whole family probably thought it was very valuable.
In either case, I don't know where that painting is currently. Perhaps in my parents' attic, or at an uncle's house. I can't even rule out the possibility it was simply thrown away.
My point is that whenever I see the claim that an artist was 'rediscovered', they were never forgotten or unrecognised in the first place. It takes a substantial amount of attention, effort, space and other resources to preserve any kind of artwork for more than a few months, let alone decades or centuries. So whenever I see more than a single work turn up by a 'forgotten' artist, you just know that that's a false claim. Somebody somewhere cared very deeply about those works and went to great lengths to safeguard them.
If you have even a handful of people actively safeguarding your work while you're still alive, then you're a very, very, lucky person. And if this is still true when you're dead then you're even luckier.