Apple Music

[grawk]

I'd say the first author didn't do his due dilligence.  The second author was reassuring the vast majority of people who don't tell itunes to overwrite the music on their server.

[Dusty Chalk]

The second author only ever discussed what happens on the primary Mac.  He implies some of the things that happen on secondary devices -- including a second Mac -- but if you read carefully, nothing he says rules out what happened to the first author. 

By all means, I agree with you that the first author shouldn't have installed Apple Music on his DAW without being intimately familiar with all the ramifications of doing so, I certainly wouldn't. 

But the second author is obviously just an Apple fan, trying to reassure people without actually saying anything.  Personally, people like that just make me more wary.