Mangrove Swamp won't update to the new look.

Summary:
They updated the Mangrove Swamp so I went to that biome in my world, and I found a mangrove swamp, and it was the same as it was in 22w14a.

What I expected to happen was...:
The Mangrove Swamp would be updated.

What actually happened was...:
The Mangrove Swamp was the same

Steps to Reproduce:

1. (Follow all the steps in 22w15a) Load a 22w14a world with an Existing Mangrove Swamp biome.
2. Go to the coordinates for that biome.
3. Observe.