Many Mac users have reported unexpected and unwanted macOS updates, despite having the 'Install macOS updates' option turned off in System Settings.
Recent incidents, like the update from Sequoia 15.1.1 to 15.3.1 on an iMac Pro, have raised concerns about Apple's ability to override user preferences.
Software update notifications trick users into unintentionally accepting macOS updates, with no option to decline or dismiss the update.
The only way to postpone or cancel an update once scheduled by the DAS-CTS system is to shut down the Mac.