Valley biome to form inbetween new mountains

In the new bedrock snapshot we got some amazing new mountains with 5 new sub biomes.  My idea is for a valley biome to generate in between these new mountains. These would be similar to what I assume are the mountain groves / meadows but generate on a much larger scale and would spawn in between mountains rather than inside them. It would have a similar effect to when a river runs between higher land and the land around the river starts to slope downwards. The valleys would follow this same principal and even possibly have river biomes running through them to simulate snow melt. It would be cool for valley biomes or even alternatively have mountain grove / mountain meadows spawn in between mountains as well as in them so that the valley look can still be created without having to go through the effort of creating a new biome