After releasing the Threshold build 10586.545 , the company is now testing another new Cumulative update for Windows 10 and Windows 10 Mobile Threshold.
The build has been compiled on 22nd August 2016. This would be another Cumulative Update which would be released to Threshold Users hopefully this week if no issues are found by the company while testing.
— BuildFeed (@buildfeed) August 30, 2016
Currently we can say that this Cumulative Update might not bring any new features but might fix some unknown under the Hood Bug and improve the performance of the OS.But we need to wait for the Build to be released and official changelog to be provided by the company for the fixes and features (If any).