Found a stronghold in my 1.16.1 Deep Warm Ocean world. Seed from Re-Create World option: 64563297. I'm playing Hardcore so couldn't use commands. I'll try to attach screenshot for coordinates. I've been playing buffet deep ocean worlds for a couple years now. First time I've found a stronghold. Didn't explore fully so I don't know if portal room generated.
MC-238676
Still in 20w18a. Ruined Nether Portals do generate in Buffet Ocean worlds, though.
Found a stronghold in my 1.16.1 Deep Warm Ocean world. Seed from Re-Create World option: 64563297. I'm playing Hardcore so couldn't use commands. I'll try to attach screenshot for coordinates. I've been playing buffet deep ocean worlds for a couple years now. First time I've found a stronghold. Didn't explore fully so I don't know if portal room generated.