Microsoft is testing a new Share sheet in the latest Edge Canary builds.
The new Share Sheet replaces the native Windows 10 share sheet, though this is still accessible via a link.
The new sheet behaves like other Edge menu pop-ups and includes specific links to social networks, and also allows you to email links to yourself.
When you want to invoke the native Windows 10 Share sheet, you can click on the Windows Share Options button.
The new sheet does not appear to be available to everyone yet, but will presumable come to dev builds in a few weeks if it passes its tests.
Source: Leo Varela