As you may remember, Skip Ahead, the option which allows Insiders to test builds from the upcoming RS_PRERELESE branch, was recently locked. It looks like the ability to join the cutting edge update branch is now restored by Microsoft.
Skip Ahead allows the user to receive Windows builds from RS_PRERELEASE with inbox app updates (Music, Groove, Photos etc) from the Store. Some time ago, this ability was locked, as the company decided to limit the number of participants for unknown reasons.
Multiple sources now report that Insiders on the Creators Update release preview ring can enable the Skip Ahead option and go directly to the Fall Creators Update.
This may indicate that development of Windows 10 Fall Creators Update is almost complete. Microsoft may want to test the upgrade process one more time before releasing the OS to the production branch.