When creating a world under the Beta with Caves & Cliffs features toggled on, no caves are generated from the surface that would otherwise have been generated outside of the bedrock beta. I understand all of the new cave generation might not be in the beta yet, even the old caves visible from the surface aren't generating. Not even ravines are generating.

This can be replicated by creating a random seed outside of the Beta, marking the coordinates down of a cave seen from the surface or a ravine. Then creating the same seed while in the beta with Caves & Cliffs toggled on, going to the same coordinates, and the cave or ravine that was once there outside of the beta is no longer generating.

I've done this on at least ten different seeds, but for the attached photos, I've replicated it using two separate Xbox One S consoles, one in the beta and one outside of the beta.
Seed: 2022110337
Coordinates: 161,87,57