Looks like a change affecting all streaming services is happening October 1st which will result in certain titles being removed. According to Qobuz this "will affect a minimal amount of titles" being removed.
Qobuz is sending out to their customer lists of affected titles they have purchased and saying to download them or lose access to them. Based on the lists I'm seeing there is no obvious connection as to why they would be pulled i.e. no specific label, genre
So looks like if you made any purchases for iTunes, etc it's best you make sure everything is downloaded...
I'm sure hutch will be seen rubbing his hands to gather, when the bellyaching starts when people's playlist get messed around.