"The new Chromium-based Microsoft Edge will impersonate other browsers depending on the site being visited. This is may be done for compatibility reasons, like properly rendering pages or how video will be streamed and played back.
"With the release of the Chromium-based Microsoft Edge, Microsoft now uses the Chromium Blink engine instead of it's original EdgeHTML engine. Microsoft has also started to add features that were unique to the original Edge into their new Chromium-based version.
"In order to support sites that utilized features that were dependent on Google Chrome or the original Microsoft Edge, the new Chromium Edge browser will switch its user agent to pretend to be a different browser."
I don't know if UA switching capability is planned as a permanent feature of Edge Chromium or is a termporary workaround, but it is interesting.
@HotCakeX I think that it is a smart move, too. Because Edge Chromium is not a released browser, UA switching is probably the best (maybe the only) way to tune Edge Chromium for specific websites.
The method now used is cumbersome, though, dependent on pointing Edge Chromium to a manual list of domains and policies setting UA for each of the domains where Edge Chromium reports as either Edge (e.g. domain":"netflix.com","applied_policy":"EdgeUA") or Chrome (e.g. "domain":"facebook.com","applied_policy":"ChromeUA").
Whether that method will be replaced/superseded with something less manual as development moves forward, I don't know.
I don't have much occasion to switch UA's, but Firefox has a User-Agent Switcher add-on that I've used a few times when working in the Linux environment. It is primarily a developer tool, though, not for the likes of me.