Let's say I have an MP3 file, and I added that to my Apple Music library on my desktop computer. Apple Music will make that file downloadable and playable on my phone, and that downloaded file isn't tied to the subscription in any way -- it's literally the same MP3 file that was uploaded. This functionality is an extension of an older feature which Apple called "iTunes Match".
On the other hand, if I download an arbitrary track from Apple Music which I didn't put there myself, that downloaded file will no longer be playable if I log out or cancel my subscription -- because those files don't belong to the user.
(I ask because I just happened to notice a $25 annual charge for that the other day... and I was like, oh yeah, I've been paying them all these years to host those 5 CDs I bought at live shows in the 1990s that aren't available on any streaming service...)
Update: Like every time this comes to mind, I almost just canceled it, but then I listened to "Track 03" by the band "djiin", purchased at Jasper O'Farrell's pub in Sebastopol, CA in 2002, and I just can't...
good to know, thanks
No, it doesn't. I literally just tested this. The article you linked to is wrong. (The site looks like a content farm, so this is hardly surprising.)
Signing out of an Apple ID will leave any subscription content downloaded from Apple Music present on the device, but unplayable. This is expected -- the user never purchased that music; they only had access to listen to it through their Apple Music subscription. Any other locally stored content belonging to the user remains playable, even if it was downloaded through Apple Music, and the subscription content will become playable if you log back in.