Player is assigned a new UUID in singleplayer

In the latest snapshot (22w17a) players are assigned a new UUID in singleplayer worlds. All things relating to the UUID are lost in this snapshot, including but not limited to Skins, Statistics, and Advancements

This can be confirmed by creating a world in 22w16a/22w16b, and then loading the same world in 22w17a. Checking the stats folder in the world folder will display two UUIDs despite it being the same player.