Does Unity delete the persistent data folder on install?

I have a Windows game that’s already available, just not on Steam. I’m releasing it on Steam shortly, but some of my testers - who already have the game, and then install it a second time via Steam - are reporting losing all their saved games, which are stored in a subdirectory of the persistent data folder. Does Unity, for example, delete the persistent data folder on install? It might also be a Steam app behaviour I guess

In fact, it appears they’re losing their entire persistent data folder, not just the saved games…