I can confirm this, too, and it's not been intermittent for now.
When I logout from my KDE session, I just get a text-mode shutdown (with blue text most of the times, butsometimes withnormal gray text).
After the step where all processes are terminated, the usplash screen does appear.
For me, too, the splash screen works properly if I shutdown directly from KDM's Session menu, or by means of a "sudo reboot" (not tried "halt" or "shutdown").
I can confirm this, too, and it's not been intermittent for now.
When I logout from my KDE session, I just get a text-mode shutdown (with blue text most of the times, butsometimes withnormal gray text).
After the step where all processes are terminated, the usplash screen does appear.
For me, too, the splash screen works properly if I shutdown directly from KDM's Session menu, or by means of a "sudo reboot" (not tried "halt" or "shutdown").