In every VV game, the skeletons vanish after roughly 24 hours if they are not given a proper burial. The mechanism for recording a peep's information has varied from chapter to chapter, though. VV5 isn't the first game with the possibility of losing a villager's memory - all the way back in VV1 (and Village Sim) it was possible to lose departed peeps if the cemetery wasn't discovered in time.

Arthur likes to give players choices in how to play the games, along with the trade-offs that come with those choices. For players who really care about preserving the memory of their villagers, the mausoleum can be completed very early in the game, but at the cost of delaying other advances and making survival a bit more difficult. For players who would rather focus on other things, the mausoleum can be delayed until much later in the game, but at the risk of losing some villager's memories.