When the game decides to despawn every single villager, the iron golem, and all the domesticated animals, except for the cats, one of the villagers should leave a note. Put up a sign explaining what happened. I've lost two villages I had been working on, both were well protected, well lit, and thriving. Then I wake up one morning to silence. Even the penned animals. Someone should leave a note. If I made a critical error, I should have some chance of understanding why it happened.