Drowned no longer spawn in oceans except for default Ocean, Deep Ocean, and Deep Frozen Ocean. Since the Warm Ocean is also affected, that also means the coral zombie nautilus is no longer in the game. This issue may also affect the Dripstone Caves biome.
You can encounter this issue by simply swimming in the affected biomes at night.
Obviously, drowned should spawn in these biomes.
As mentioned before, they do not.
Can confirm.