Increased Lava/Magma Cave Generation

Now that the new cave and cliff generates currently new caves below zero. My idea was that more stone would gradually be replaced on the walls with magma blocks, similar to the earths crust near the mantle would turn into molten rock. Or have more lava generated caves.
The reason why I am suggesting this is because as of now, there seems to be less lava cave generation in the snapshots.
The only problem I can see with this is how this would work with deep dark generation. Because this is a snapshot, this is all bound to change anyways.