I thankfully have a local backup of the photos I took, but when a phrase like "backup" is used, it is implicit and understood that there is a "restore" mechanism.
Google Photos lacks a "restore" mechanism, and it sounds like the same is true of Apple Music.
Google Play Music also does the matching/mismatching thing.
An uploaded Ladytron - Gravity the Seducer was replaced by a remix album but remains tagged as if it's the original. This is probably due to them not having the original, and this was a 90% match based on tags... but 90% is not good enough. I worked in the music industry and have so many demo tapes, master cuts that were not subject to post-production, etc. I want the version I have, and not some approximate guess at something similar-ish.
This isn't just an Apple issue.