I’ve seen some artists promote the YouTube “topic” channel over their own channel. E.g., Gjaldulei’s “band media” page links to https://www.youtube.com/channel/UCr4ZDeKdEM0w87rd7QgN2Vg as “YouTube / Google Music”.
As long as these topics have a unique URL, I don’t see why we shouldn’t link them. Maybe the current relationship needs to be reworded though.
It’s certainly not a channel, and I have been removing them when I see them. If we want them to be allowed, then we should either rename the relationship, or have a separate relationship for them. They’re 99% of the time autogenerated crap including, AFAICT, unofficial stuff we generally would avoid linking to, so I’m not a fan tbh.