Microsoft are getting close to the final release of the Windows 10 Fall Creators Update as they a new preparation patch is being released to the slow ring. The patch KB4022716 is rolling out to Windows Insiders on the slow ring and prepares the system for the Fall Creators Update. The update simulates the way the Fall Creators Update (Redstone 3) will roll out to general Windows users.
With the Windows 10 Fall Creators Update Microsoft are changing how they target slow ring devices. Rather than them all updating at once users can manually check for updates and get the build straightaway or wait for the device to get the build automatically.
Via Windows Blog