Cave world types no longer generate the biome specific features such as grass blocks, trees etc.
The cave biome would generate as normal
World type caves does not generate 3d biomes or below y0
When the dripstone caves is a single biological system, the driptone block and pointed dripstone can be generated on the ground
Complete un-yes of a mess of the world generation of Cave Style Buffet worlds (Different from my last bug report, you gotta believe me)
The surface in single biome worlds set to use nether or end biomes consists of grass blocks and dirt