Chunk blending seems to overwrite new terrain to too much effect, even if new terrain would line up perfectly with old terrain.

Here's an example.
Image 1 is a world generated in 1.19
Image 2 is the same seed generated in 1.20
Image 3 is the first world with the area where the Cherry Grove biome would appear in 1.20 deleted and re-generated.

Obviously, blending chunks are moving the old terrain into the new terrain, but in this instant its quite unnecessary how much of the chunks become blending chunks - the entire area of the Cherry Grove was removed.

Image 4 is the first world with a significant amount more area removed, much more than just the Cherry Grove, in this one, the blending chunks are far enough away from the Cherry Grove to generate it perfectly how 1.20 intends it to be.