https://wccftech.com/no-windows-10-19h1-preview-build/

Earlier this week, Microsoft released a fresh new Preview Build to Windows Insiders in the Fast Ring who are currently helping the company test the upcoming Windows version codenamed Windows 10 Redstone 5. But, nothing was released from the Windows 10 19H1 RS_PRERELEASE branch.

As reported last month, the company has also concurrently started to test the 2019 edition of Windows 10 with the help of Skip Ahead Insiders. However, no new build has been released for these Insiders since Windows 10 Insider Preview Build 18204’s release on July 25, which was exactly the same as the Redstone 5 Preview Build 17723.