I have a world that I was playing on 1.20.1 with the bundles experiment enabled and recently updated it to 1.21. However, when I updated my world, the wolf variant features weren't added with the update. I can access the armadillos and wolf armor, but wolves still spawn as the pale wolf no matter what. They also won't spawn in biomes such as the wooden badlands.

I attached a screenshot of me finding a pale wolf in the forest post-update.