Some details: iOS 16.1.1, iPhone 13 with USB cable to a Toyota Camry. MacOS 12.6.1 (although my other devices weren't actually involved.)
I mainly listen to music in the car during my commute, so I very rarely ask Siri to play anything except through CarPlay. Several times in the past I've asked Siri (CarPlay) to play xyz from my Library and the response has been something to the effect "playing xyz from Apple Music", but it didn't play anything (or maybe played from my Library, as asked - I just don't recall.) It never enrolled me in Apple Music before.
This time I had been listening to an album of classical music earlier, and when I tried to play the album again (manually) it only played the first cut, not the Album. So I asked Siri "play the album xyz from my Library". (Specifically I wanted the album of Bach French Suites") The response was "playing xyz by Johann Sebastian Bach from Apple Music", but instead of playing that it populated the up next list" was a totally random "playlist" of maybe 70-100 unrelated cuts from my library, many of which I hadn't played in years. It may be important that I have Cellular Data OFF for Apple Music, so technically it couldn't play xyz from Apple Music.
Then I was informed I had signed up for the 1 week free trial of Apple Music (I don't recall if that was while I was still in the car or only by email when I got home.) I NEVER asked to sign up. I'm concerned when the "free trial" expires I'll automatically be charged the monthly fee for Apple Music, which I REALLY don't want. I'm also concerned that Apple Music will start "optimizing" my Library by switching out versions of my music for whatever you've got on-line. This would really suck for my classical music Library where I have multiple versions of the same pieces performed by different artists, orchestras, etc.
Why is Apple Music being accessed when I've never asked for it? Also, why has Apple REMOVED the preference to "not access Apple Music" from the Music settings? (or at least, where have you hidden it?)