Transformando o comentário de @gravity em uma resposta, um tópico da lista de discussão do Gnome diz que:
runDialog: Disable restart command on wayland
Clients can be expected to deal with the WM going away temporarily, but not the display server - so when running as wayland compositor, a restart is generally a fancy way of killing the user session, and there's little we can do about it except for preventing the user to shoot herself in the foot by throwing an error.