It can be made to work in wayland too. It’s just doesn’t load the library for wayland session.
gtk3-nocsd won’t work well under GNOME Session. GNOME uses headerbar for dialog as well. And it does’t remove the title. For example, try CTRL+H in gedit. Also there seem to be some issue with gnome-disks
And we are talking about default options for gtk3-nocsd. Upstream disables it for GNOME. (for some reason it’s not working). But user can override this any time by settings
In, /etc/X11/Xsession.d/51gtk3-nocsd-detect I found out that it uses
readlink /etc/alternatives/x-session-manager to detect if it’s gnome or not. But it’s not reliable way to detect because both ubuntu and unity use gnome-session. So may be we can patch that part.