"Beginning no earlier than July 30, 2020, Microsoft will update Microsoft Edge Legacy to the new Microsoft Edge browser by Windows Update on Windows 10 devices in education and business. This update will not impact devices in education and business updated by Windows Update for Business (WUfB) or by Windows Server Update Services (WSUS). Updates will target education devices first to accommodate back-to-school timing. We will share a business timeline at a later date."
Microsoft has made a Blocker Toolkit available for any organizations that either don't want or aren't ready for the new Edge. Because Chromium-based Edge is now a separate downloadable app, users can opt to uninstall it if it ends up on their PCs and they don't want it by going to Apps in Windows settings and clicking the Uninstall button for Edge. (I have heard from a user recently who said this uninstall option is grayed out for him, making it impossible to get rid of the new Edge. Anyone else having this issue?)
Update: Aha! It turns out once you use Windows Update (vs. manual download) to update Chredge, you lose the ability to uninstall it. Thanks to Thurrott.com's Paul Thurrott for letting me know.
As Microsoft officials note in today's blog post, Internet Explorer 11 will remain on devices when the new Edge is installed. The new Edge also "will respect your previously established default browser choice," Microsoft officials said.