Wooded badlands don't generate their distinctive terrain below height level y=100, causing inconsistencies due to how this biome no longer generates on plateaus anymore.
There are instances where you would find this biome only below y=100, and it wouldn't generate any grass, coarse dirt or trees. Which might be confusing and misleading.
Expected result
Wooded badlands would generate trees, coarse dirt, and grass below y=100.
Observed result
Wooded badlands generates as regular badlands instead.
How to reproduce
Create a single biome world of wooded badlands.
See the terrain around.
This is intentional, since in wooded badlands, trees are only supposed to generate above a certain altitude.