Even if Sony keeps a token factory or two open to produce blu-rays, I'd imagine we'll see fewer and fewer new releases. Maybe we'll only see them as part of collector's sets that have enough margin to afford a cut of the more limited supply.
This feels like the beginning of the death spiral for blu-ray. Sales aren't going to go up enough for it to be worth it keep factories going, much less spin up new ones.
Years ago I did a podcast[0] on physical media and hypothesized UHD would be the last physical movie format (and was shocked that it was even a thing).
The next two years are probably going to be a mess as collectors snatch everything up annd inventory gets cleared out.
0 - https://podcasts.apple.com/us/podcast/cherry-bombs-the-under...
UHD bluray isn't really a new physical format. It's the exact same physical format as regular bluray. They didn't change a thing except move some previously optional parts of the bluray spec (like three layer discs, and 33GB per layer) to being compulsory.
I don't think we have ever seen something like it before. A new media format that breaks backwards compatibility, yet uses the exact same physical medium as the previous version. Some people did attempt it with HD movies on DVD, but the attempt failed so badly I don't think it even counts.
Its very existence was a very strong signal Bluray would be the last optical disc format. And the launch of the PS5 without a new optical confirmed it.
It has Dolby height sound encoded for x.x.4 systems