https://www.bleepingcomputer.com/news/microsoft/how-to-run-classic-and-chromium-microsoft-edge-side-by-side/

In January, Microsoft will ship a Windows Update on all versions of Windows 10 to replace the classic Edge with the Chromium-powered Edge browser. The migration happens during a Windows Update and the new Edge hides the old Edge after the update completes.

Microsoft says the update will only hide the browser on Windows 10 and the classic version of the browser won't be removed, at least for now. For businesses and those who need it, there will be a new way to launch classic Edge after the Chromium Edge is installed.