For those in the Insiders program in the Fast Ring:
UPDATE 10/2: We have released Windows 10 Insider Preview Build 16299.15 to Windows Insiders in the Fast ring. As we prepare to release the Windows 10 Fall Creators Update to the world on October 17th, we will now start testing out servicing this build with the Cumulative Updates via Windows Update.
While not a complete build, this is a new update being pushed out as a Cumulative Update. Same build, with a minor revision – 16299.15.