https://www.bleepingcomputer.com/news/microsoft/microsoft-replaces-edge-legacy-in-latest-windows-10-dev-build/

Microsoft has started replacing the legacy version of the Edge browser with the new Chromium-based Edge in Windows 10 Dev builds.

This change is rolling out to all customers installing Windows 10 Insider Preview Build 21313, offered through the Dev Channel and available after joining the Windows 10 Insider Program.