https://wccftech.com/2021s-first-windows-10-preview-build-is-out/

Image: @WindowsInsider (Twitter)

Microsoft has released its first Windows 10 Insider Build. Today's Insider Preview Build 21286 (RS_PRERELEASE) is available for all the Insiders in the Dev Channel of the Windows Insider Program. Last few builds of 2020 were divided between two subsets; however, going forward all Dev Channel Insiders will be receiving the same builds.