Tests with the macOS Sierra 10.12.1 remain intense. Less than a week after the second, Apple today released its third beta version (build 16B2338c) to developers.
Although the update did not show anything visually new in Sierra, it is speculated that it is being prepared "in a hurry" to equip possible new Macs to be launched this month.
MacOS Sierra 10.12.1 beta 3 is already on the Apple Developer portal and on the Mac App Store, for those running a previous beta. Soon, it should also be made available to members of the Apple Beta Software Program.
Update · 10/03/2016 s 15:01
Apple today also informed the The Loop that macOS Sierra becomes automatically downloaded, in the background, on the Macs of users who have this preference enabled. It will not be installed automatically, however; when finished downloading, offer the option of being installed to the user.
Obviously, anyone who wants can disable the automatic download option as well as cancel and delete the Sierra download. The system will also do this automatically if, for example, the Mac starts running out of space due to the download.
Update II · 10/04/2016 s 14:33
As expected, macOS Sierra 10.12.1 beta 3 is now also available in the Apple Beta Software Program.