A planned October 2021 release date for Windows 11 has been accidentally leaked in support documents from both Microsoft and Intel. Windows partners had until September 24th, 2021, to submit their drivers for compatibility if they wanted their drivers to ship with Windows 11, version 21H2. Intel has removed the name of the Windows 11 update from the support document, but an archived version shows the original compatibility list. Microsoft may adjust the release schedule, since the release of Windows 10 has been released every fall, either in October or November.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-11s-october-2021-release-date-hinted-in-support-docs/