I checked the sound files and sound definitons. The nether is still missing exactly 16 ambient sounds. Nether Wastes is missing 1(mood5), Warped Forest is missing 10(mood 5-9 and creak 1-5) and the Basalt Deltas is missing 5(ground 4 and active 1-4).
Why is this "works as intended"? The old versions of Bedrock didn't have this issue?
Present in 1.16.200.53
There's a possibility that the Basalt pillars can only generate on netherrack based on the screenshot on the comments.
Affects 1.16.20.50
Still in 1.16.20.50. Hope it gets fixed because the biomes look ugly compared to Java.
In 1.16.20.50.
In 1.16.20.50.
MCPE-125235 is a different issue, though. This bug refers to just magma block generation not the sea floor.