The Bug
Despite biomes like edge & hill biomes no longer generating they are still accepted towards the adventuring time advancement
Reproduce
Make a single biome with a biome that doesn't generate anymore (like Giant Tree Taiga Hills)
Kill a monster to activate the advancement screen
Go down to adventuring time
❌ Notice that despite it no longer naturally generating it still counts towards the advancement
Expected Result
The non generating biomes no longer count towards Adventuring Time
This is fixed in 21w40a