Different kind of metadata, I think; the Verge article seems to be talking about the data that goes to PROs[1] and CMOs[2] which is then used to calculate splits and payments based on data from people like Spotify, Apple Music, etc. ("they had missed out on payments for 70 songs, going back at least six years" is stuff I've seen before w.r.t data just not being sent to the PRO/CMOs from a label.)

[1] https://en.wikipedia.org/wiki/Performance_rights_organisatio... [2] https://en.wikipedia.org/wiki/Collective_rights_management

Indeed, MusicBrainz contains the names of songwriters, but not the organisations they belong to