Edge is already available on iOS, Android, Mac, Windows 10 and Windows 7, and we have known since December 2019 that Microsoft is working on Edge for Linux also, after Microsoft confirmed the development at Ignite 2019.
Now at Build 2020, a Microsoft Azure engineers was spotted using Microsoft Edge for Linux.
It was only flashed up briefly, so we only know that it looks largely the same, but no further information was provided.
Having the browser available on the open-source operating system would make it easier for developers using the operating system to create web sites and web apps which are Edge-compatible, making it an advantage for Microsoft despite the rather small potential audience.
It is not clear when the browser will be available, but it appears likely it will be at the latest sometime this year.