I don't feel like doing a deep dive but I clicked around and I'm not 100% convinced it's (all) AI. Each album links back to an artist and several have been making music for awhile. One of the albums I clicked is a decade old. That said, there were several with only 2024-2026 releases. So I don't know.
I don't listen to dark ambient so I don't think I'd be able to spot it by listening