With today’s release of Windows 10 Insider Preview Build 18252, the 19H1 development branch has formally moved over to both the Fast and Skip Ahead rings. This build introduces some new features as well as fixes some bugs in Task Manager. […]

from https://www.bleepingcomputer.com/news/microsoft/windows-10-insider-build-18247-19h1-released-and-moved-to-the-fast-ring/