New animal variants not spawning

Animal variants do not appear to spawn using spawn eggs, nor in the correct biome.

Steps to Reproduce:

1. Create a new world

2. Using a spawn egg, spawn a chicken, cow or pig in either a hot or cold biome.

3. Notice the temperate variant spawns.

Observed Results:
None of the new animal variants spawn.

Expected Results:
New animal variants should be spawning.

Screenshots/Videos attached: Recording 2025-02-05 130021.mp4