Not even thinking about whether the rip is bit perfect there's no expectation Apple even keeps serving up the version of the master you originally bought and wa

Not even thinking about whether the rip is bit perfect there's no expectation Apple even keeps serving up the version of the master you originally bought and want to keep. It's not even about the rip, it's that they might swap in a rip taken from a different version of the recording. Many albums get remastered.. most of these cloud services will just drop in the new version and the old one is gone. IIRC Apple might be pretty good about this, but you still don't want to surrender control. In any case there have been many albums where the remaster has worse audio quality than the original. If you bought the original you might really want to hang onto that version. The most egregious form of that kind of thing is things like movies like Star Wars where the later editions are different edits of the movie. If you wanted the original you wouldn't be happy your copy was swapped out with the new edit. In the case of music this is often just remasters having a lot more dynamic range compression and heavily boosted levels, but that can still be very objectionable.