"Glitches"...how about these.
Apple now does the same thing with eBooks! I had about 200 Comics and another 100 eBooks in my iBooks collection that I downloaded/purchased from other sources like Bittorrent's Big Bundle. iOS9.3 finally support eBooks/iBooks on iCloud. It uploaded to the service and then when I decided I didn't want to deal with iCloud and turned it off. EVERY non-iTunes purchased book was DELETED from my account AND off my hard drive! Luckily I had it backed up. But that's just BS.
I just went through an identical situation, but with iBooks instead of Apple Music. I run an eBook store so I have 500 PDFs in iBooks. New update came to allow you to share PDFs over iCloud to all devices, so I clicked to turn it on. It uploaded the books, then deleted them all from my computer. When the Metadata was incorrect on my other devices, I turned iCloud for iBooks off. Then, of course, iBooks was completely empty, books lost forever.
I had a Time Machine backup and Apple Support was able to help me find the hidden iBooks folders I would need to restore to get my books back. I definitely won't be turning on any iCloud file sharing services without a very recent backup.
I think it is deliberate from Apple, not a mistake.Yes I have iBooks issues but nobody talks about it as I don't think it's widely used- I have lots of audiobooks and it's so confusing!!
I have a massive iTunes library, including tons of music not available on Apple Music, or iTunes in general. I have used Match since it debuted, as well as a continued subscription to Apple Music. I have used Match to move the same massive library to new computers, over time. I have never lost a song.
I think theses services work as intended, and work very well. This sounds like user error to me.
I hope Apple's fix won't interfere with your already perfect world. That would be... curiousI've never experienced this bug (if it really is happening, and is not user error or user confusion). Apple Music just works perfectly as intended to me every single day.