The developer working on integrating network display functionality into GNOME Shell shared short video clip to the GNOME sub-reddit […] the feature adds a “screencast” button to the row of actions in the Quick Settings menu. Clicking this opens a modal picker where the user can select any Miracast or Chromecast compatible displays on the network.
Finally, this is something Linux is severely lacking. Every Android phone today comes with screencast integrated. Connecting it to any projector with WiFi capability is no issue at all.