Villagers are being Thanos'd and we don't know why - please help!

[SupersuMC]

The issue first became apparent with Riyadhcraft's town at least a couple of weeks ago, when he and his friends noted villagers disappearing. Now the issue is starting to become server-wide, with at least 5 villagers missing from my marketplace, the staff of my aquarium disappearing - first the recently promoted Journeyman and now his replacement and the other staff member - as well as a villager transported to my lighthouse, and several villagers disappearing from BitterOlive's trading hall. If this is a problem with "excess" villagers or something happening with the server data, please let us know - we need answers!