Minecraft wiki entry for Before_1.18, associated text: In Java Edition 1.18 and Bedrock Edition 1.18.0, Overworld terrain generation was rewritten to become more varied and independent of biome generation. This made many biome variants that were in the game redundant, as the only difference between their regular counterparts was the way terrain generated in them. As a result, most variant biomes were removed from the generator. In Java Edition, these biomes were merged with their normal variants, while in Bedrock Edition, these biomes still exist, but remain unused.