If I use Google's Structured Data Testing tool, to check a MusicBrainz artist, it reports an error "Missing '}' or object member name" suggesting that the JSON-LD is not structured properly, and Google and MusicBrainz are probably not getting any value from the information.
I believe that Google implemented the JSON-LD schema.org for MusicBrainz, but they might not be aware of the issue, and I have no idea who the contact might be. It would also be useful if Google supported JSON-LD schema.org:
- For Events
- The enhanced Music schema.org, in particular the new "potentialAction: ListenAction," which links audio recordings to the data