@FruitBreak, a little late here, but this works because capable url associations (launchable protocols) for Microsoft-Edge include the following: http, https, microsoft-edge, and read. The particular protocol in question, Microsoft-Edge, is specific to Edge, while others are subject to default app settings (“choose default apps by protocol”). If edge is your default app for the read protocol …
https://stackoverflow.com/questions/31164253/how-to-open-url-in-microsoft-edge-from-the-command-line

