It is great to see this eventuate and I hope development continues.
Screen sharing crashes teams app, Fedora 30 Workstation / Gnome desktop / Wayland. As this is Electron, it is worth noting the same problem was not observed using genuine Chrome browser
When the crash occurs, the app "restarts" and may require a new login.(actual process does not finish)
Video and audio work well, did not ask permission to use mic, cam.
Closing the Teams window leaves app running - tray widget sort of thing. Unclear if mic/cam would still be active (hot mic danger zone, perhaps)