Following the release of the third beta of macOS Sierra 10.12.1, it’s been discovered today that Apple will begin downloading the update package for Sierra to all supported Macs that haven’t upgraded to v10.12 yet. The Loop first heard word about this change today and released a full report with additional details you can view here.
In a nutshell, this automatic download will only store the package necessary to install macOS Sierra on your Mac. This means you’ll still have to manually initiate the installation, but this is a good thing since there’s bound to be people who simply don’t want the new software. In addition, you’re able to opt out of automatic macOS updates by unchecking System Preferences > App Store > Download newly available updates in the background.
It’s worth noting that if you don’t have enough storage on your Mac, the Sierra update package won’t download automatically, even if you have the option enabled. Also, when a user has little space available on their computer but has enough for Sierra to store itself away, the package will automatically delete after the installation is complete. This is usually a step users have to take manually, so it’s nice to see it automated here.
A notification prompting you to install Sierra will appear in your notification tray once the necessary files are loaded onto your Mac. You can either choose to ignore it or take action by beginning the installation process. Of course, this whole ordeal is to simply grow Sierra’s active user database, so don’t take this prompt as a security measure or something more serious like a requirement.