Apple recently rolled out some changes in the iOS 14 beta to allow users to switch the default web browser from Safari to Chrome, but it looks like Microsoft is now finally in on the action too, As noted by Neowin, it is now possible to change Microsoft Edge to the default web browser in the latest iOS 14 beta.
This ability was delivered in the latest beta version of Edge on iOS via Test Flight. When this version is installed, you get a full-screen notification inside edge from Microsoft that will take you to a page in iOS where you can change the settings.
According to Neowin, it seems as though only Google and Microsoft have opted to support this ability to change the web browser. Firefox, Opera, and other web browsers have not been updated to support it yet. Additionally, emailing apps like Outlook or Gmail also haven't been updated to support the switching, too.
It's likely we could hear more about this once the general release of iOS 14 comes around this fall. Apple is holding an event tomorrow, September 15, so more information is likely to come out then.