Microsoft is rolling out a new cumulative update build for Insiders on the Release Preview for PC and Mobile today, featuring more bug fixes and other under the hood improvements as most cumulative updates do. Today's update brings the Anniversary Update to build 14393.479, up from build 14393.447 or 14393.448 for PC and Mobile.
Today's update for PC is called KB3201845 and simply referred to as "14393.479" on Mobile. If you're in the Insider Program on the Release Preview ring, checking for updates now should see that update ready to downloading and installing.
We'll update this post when the changelog for this update is released detailing what's new and improved. Until then, make sure you get this update downloaded now!
Thanks for the tip, eiriklb1