Trees that require saplings in a 2x2 pattern will not grow if the chunk was loaded before 20w19a. Bone meal and ticks do not work, so the only way to get them to grow in worlds that loaded before this snapshot is to enter a chunk that was loaded during the current snapshot.

What I expected to happen was...:
2x2 trees normally have a chance to grow every few ticks, and bone meal can make them grow instantly.

What actually happened was...:
They will no longer grow in outdated chunks even if the world is loaded in the updated snapshot.

Steps to Reproduce:
1. Load some chunks in an older snapshot/update.
2. Update the world to 20w19a-20w21a.
3. Plant 2x2 trees and bonemeal them in the previously updated chunks.