I have added house parties/birthdays where bands have played:
My work has a heritage team on-site, and it’s been interesting working with them. You would think they would be assigning a heritage ‘status’ to data that they value and collect. In fact, it’s the opposite. They often complain about the fact that so much ‘mundane’ everyday stuff is missing/thrown out and not valued, even though it can give us the most accurate impression of everyday life. This includes current things (heritage is different to ‘history’ in this respect).*
Anyway, I use MusicBrainz to map the local scene that I have been included in, and that without MB would have little to no documentation. Sometimes niche scenes are of importance culturally, or just to someone, later but information is hard to find because nobody considers their output at the time noteworthy enough.
Because MB is well equipped to deal with massive amounts of data I’m very glad to be able to add so much ‘minor interest’ material - which is also MB’s biggest advantage over other music sites (though Discogs does the same - allows any release - and owes much of it’s popularity to that as well).
Just wanted to raise the flag in support of our current notability requirements - none
*Vaguely related, I’m dying waiting to be able to upload gig posters, older events I added are disappearing from Facebook with all the data!