On Xorg I found that doing ALT + F2 and then doing r would work in order to restart gnome-shell after an update, however with Wayland on Ubuntu GNOME 17.04 and GNOME 3.24 I have found that I get a message saying:
Restart is not available on Wayland
Given that in 17.10 Wayland will become the new thing with GNOME, is this feature going to be supported in future through Wayland, or if not then, why?
In an Xorg session one can restart GNOME shell without losing application state as applications are running against a separate server (X). But unlike Xorg in case of a Wayland session GNOME shell is not separate from the Wayland server.
So there isn't any way to restart GNOME shell in Wayland without losing application state as the display server also goes down. It's similar to restarting X server in an Xorg session.
That is the reason why this shell restart option is disabled in Wayland (recall that usually the key sequence to kill the X server is also disabled by default in the Xorg session) and there will probably never be any non-destructive way to restart GNOME shell in Wayland.
You may see this GNOME bug report for details.
