I wish Apple would separate the updates of their bundleware from their OS. Some of the major updates have meaningful changes to the underlying OS (gatekeeper, SIP, etc.), but others - like this one - are primarily changes to frills like Messages, Notes, Safari and other Apple-native apps that I don't even use.

I have no problem with Apple bundling these apps and making them work seamlessly together, and I don't even mind that they're all updated simultaneously (except for Safari, which I wish I could update independently without relying on the "Technology Preview" beta channel). But I do have a problem with upgrading my entire OS and disabling the new bloatware features just because I want to keep auto-updates enabled. I used to delay updating and then would end up way behind, which is why I enrolled in auto-update. But now it feels like I'm being held hostage to their update schedule.

And for what benefit? There are hardly any useful OS-level changes in this release, but there are a bunch of new features I'll need to disable (while hoping the next auto-update doesn't break my external monitor), all powered by freshly written code contributing to an expanded attack surface. If I had my way, then I'd take the OS updates and skip all the apps. Keep the attack surface small while still meaningfully improving the core. I don't care about the rest.

You know what would be even better? If you could reliably uninstall all this junk or not even install it at all.

Every time I hit some button on my keyboard and the Music app opens asking me to create an account I am reminded how hostile all commercial operating systems are.

I agree with you. Apple Music is particularly annoying. I recommend this free little utility: https://github.com/tombonez/noTunes