[skat20phys]

Not exactly what you mean but operacast lists opera streaming broadcasts from around the world:

operacast.com

It's pretty old-school but I've found the schedule pretty up-to-date. I've also noticed that some of the programs aren't opera per se but "opera adjacent", like choral music or instrumental music by opera composers. My impression is that there are some programs that regularly stream operas but at any given week might offer something else.

My sense is that there's a lot of opportunity for a well-done classical streaming service. A lot of the traditional channels don't quite work because their catalogue isn't deep enough or their metadata structures are weird and unhelpful (for example, it's impossible to sort by composer alone).

[sonar_un]

Opera cast is generally pretty great, but it is pretty manual and they do miss a lot of things going on. There are now lots of classical streaming only services like Primephonic, Idagio, and others that take care of the metadata problem.