DRM implications of iCloud Library?
Ecosystem in question:
2012 Mac Mini, Catalina 10.15.7, Music version 1.0.6.10, iPhone XS Max, Apple TV 4K, Apple Music Subscriber
Synopsis:
I have recently enabled 'Sync Library' on both my iPhone and Mac. I understand that if you are a Music Subscriber and you enable 'Sync Library' on the Mac, it then switches on 'iCloud Music Library' and attempts to compare your local library to Apple's database. Anything that's a 'Match' (as in the older iTunes Match) doesn't upload, but anything not available online, *is* uploaded, DRM Free. So the end goal is you have everything, everywhere, in essence. I say 'attempt' because I am now left with a big pile of grey boxes that won't play, but I will gloss over that.
Query:
My main question is, what are the DRM implications of uploaded music that wasn't purchased from Apple? I have a large number of files that I imported into iTunes, spanning several years. I can't remember where all of it came from originally, could be from vinyl, CD, tapes, assorted recordings etc.
If I were to tick 'Publish on profile and in Search' and someone plays a track on Music, and says "Hey, that's my music, how did that get here?". We live in an extremely litigious, petty world and I would like a definitive answer on that, if possible, please? Could that be why some of my content is greyed out? Apple boffins are doing background DRM checks on my uploads?