How many watts is that window deicing system? If you were to look at cockpit items that could possibly cause a fire, a window heater would be near the top of the list. High current next to condensation and vibration is a really good way to cause a fire, as many boaters have discovered.
Contrary to popular belief, circuit breakers do not protect you from fires. They protect you from one condition that can cause a fire but they do nothing to save you from a loose connection that heats up and melts the insulation. If there was resistance in the heating circuit the window would not get to temperature and the thermostat would keep calling for more heat, and the loose connection would keep getting hotter. I'm sure it is not that simple or it would happen more often, but I suspect we are about to learn a lot more about window deicing systems.
The three messages related to the RH window are telling us something.