According to the description of navigator.share() on MDN Doc, the Promise returns by navigator.share() will be fulfilled when a share action has been completed.
Although Edge (on Windows) starts supporting Web Share API after version 79, I find the Promise returns by navigator.share() will be fulfilled as soon as an OS built-in sharing panel popping up, even if a user hasn't clicked on any buttons on the panel.
It is different from how I see Safari and Chrome handle the Web Share API callback. As far as I know, both Safari and Chrome only fulfill the Promise from navigator.share() after a user has "completed" a share action on the OS sharing panel.
I really appreciate what you guys did for the new Edge. But I wonder if the Microsoft Edge Team will improve the design of Web Share API in the future.