I think it is in certain circles. For Google, obviously, in particular. Many of their new sites launch completely incompatible with Firefox and Edge. Some of the frameworks they push, like Polymer and Angular, have been repeat offenders in the past, which leads web apps built with them to also be broken.
To be clear, it still specifies "Edge" in it's UA string and can be specifically detected. And just about every browser now mentions Mozilla, Chrome, and Webkit in their UAs.
