Granted .. but it's still a fork of "gnome-session-fallback" part of the shell .. you only have to run gnome-session-fallback in Ubuntu to see Cinnamon is the same thing in green, with the slab menu.
Really it's just a "tweaked" gnome-session-fallback.
So (unless I'm mistaken) Cinnamon won't be able to move beyond Gnome 3.(whatever came before 8 ..7 ?).
I can't see how Cinnamon won't be affected by this, unless they fork a lot more of the code