Villagers all despawned

I loaded into my world after the last update and found my entire villager trading hall empty. I'd been playing on Peaceful for the last few weeks to just relax while I wait for the next big update changing mob spawning, so I know it wasn't a zombie outbreak or anything, they're just..... gone. I've had one or two vanish on occasion over the months in this world, but on this last update, about 30 of them just vanished all at once, and I only just found out after multiple autosaves happened in the background, so I don't have the option of rolling things back to try and get them back. Not playing on a beta version or anything, just the standard update list.