The recent announced option Skip Ahead Microsoft on the early access to early builds of Windows 10 through Windows Insiders, no longer accepts new members.
The option gave Insiders access to the new builds of Redstone 4, the code name for the significant update of Windows 10 expected to be released in the middle of 2018, after updating Windows 10 Fall Creators Update, codenamed Redstone 3, which we will see online this September.
Skip Ahead, as the name suggests, allowed some Insiders from Fast Ring to have access to Fall Creators Update versions, where most new features are not likely to be added since we are close to the big news release.
Last week, however, Microsoft had not released new Redstone 4 upgrades to insiders registered in Skip Ahead.
Skip Ahead is still there, of course, but as MSPoweruser pointed out, the program does not accept new members.
“Skip Ahead is now closed. If you select this option, the setting for Windows Insider Program will be restored, "the new Windows settings report.
As Microsoft recently explained, it "forked" Fall Creators Update into the RS3_RELEASE branch, which was formerly RS_PRERELEASE.
Those who chose Skip Ahead will now receive updates from the much less stable channel well before release, while the RS3_RELEASE branch channel will become more stable just before its possible public release.