This just happened to me on a bedrock 1.17.2 realm, i had made a wooden hut with only a trapdoor entrance and lit the whole place up. I had 11ish villagers including a 18 emerald mending book librarian, when I come back only the zombie villagers i had cured remained meaning I lost all the enchanted book librarians i had bred and then gave perfessions and traded with. 

Earlier on a diffrent realm i had about four named axolotls in a lit up water tank witch was lit up. When i rejoined eager to see my new friends only one of them remained. It had crushed my spirits about the new update

Update: Apparently not even the unbreaking three villager i cured named and traded with survived because when i rejoined he was also gone