I really don't see what good that is when considered in the greater context of the Linux desktop paradigm, wherein any application running under your user almost certainly has write access to your entire $HOME, including the ability to tamper with your shell configuration, edit your $PATH, and do all manner of nasty subversive shit. To get any real security benefit from Wayland over X, you'd have to abandon the entire Linux desktop paradigm and use a completely new ecosystem as different from the traditional linux desktop as Android is.
If you just use Wayland as a drop-in replacement for X (as GNOME/Wayland and KDE/Wayland are essentially doing), you're still screwed six ways to Sunday.