I decided to upgrade a World from 1.14, this World has gone trough different Snapshot during the Development Stage, at the end none of those Snapshots gave me a major problem like this one that just happened recently in this 1.14.1 Pre-Release 1.

At first I noticed the Villagers not even attemping at Pathfind to their Work Station, since I upgraded the World during Nightime they were sleeping, so they could remember their Home Memory, later on I decided to check their Memories with the /data Command. I noticed they lost any Memory, I also noticed some Villagers having Babies, a hint that some Villagers couldn't even remember their Bed Coordinates so basically these Beds were not claimed and the other Villager could have Babies without any problem, previously they just attemped to have Babies but failed since there was no more Beds for Babies.

Using /data on this Cleric

You can see only keeps the Home Memory

And this one showed up since it was previously sleeping, otherwise it would have a Blank Memory.

But notice other things like Gossip and Trades still intact, in this Villager for example