https://wccftech.com/windows-10-may-2019-update-almost-here-time-for-insiders-to-check-settings/

Microsoft has pushed the public release of the next version of Windows 10 to next month. Windows 10 May 2019 Update aka version 1903 will be made available for Windows Insiders in the Release Preview ring soon. However, now that the development process of version 1903 has been completed, the Windows maker will soon merge the Fast ring with its thrill-seeking Skip Ahead Insiders.

Skip Ahead has already begun testing Windows 10 2020 and with Fast ring now done with 1903, Microsoft announced that Insiders should verify their desired Windows Insider Program settings to make sure they are on the ring they want to be on before Microsoft starts pushing 20H1 builds to the Fast ring, as well.