https://www.theregister.co.uk/2019/02/21/windows_insider_builds/

In a busy week for Windows Insiders, Fast-Ring fans got a fresh build of Windows last night, hot on the heels of a new preview of the Windows Admin Center.

Having sent Skip-Ahead testers into the future with a 20H1 build of Windows 10, Microsoft has now shared the Linux love with those remaining on the Fast Ring and testing 19H1.