When the apps are shipped bundled with the OS by the same company, and use new system framework/API features that are part of the OS what is really the distinction?
iPhone mirroring, video conferencing and window tiling actually use system frameworks, so it's okay to present them as OS features.
New versions of Safari are already available for older macOS versions through System Update for a few years, I've already downloaded Safari 18 on my Sonoma. And for Passwords, Messages, Notes and Maps there's no legit reasons why newer versions can't be distributed through App Store, other than using their new features as a promo for their new macOS...
Proceeds to talk about new App features instead of OS ones.