That list issue you mentioned really confused me, so here’s what’s in the article about it:

The judge also noted that Spotify’s agreement with Kobalt did not include a database of the songs it could, and could not, stream.

“Kobalt’s primary stated reason for that approach is that the catalogue of a large administrator like Kobalt would be routinely changing, rendering any list almost immediately out of date,” she wrote.

So…

• It’s not Spotify who’s behaving weirdly here but the rights holder and
• the judge doesn’t just seem to be okay with it, but this is mentioned as another thing that added to the impression that the rights holder made it deliberately hard for Spotify to properly determine if it had the rights to stream a song.