I'm inclined to agree with you, but the Student Reference Book specifically says the vehicles theft alarm system "disables the ignition system". Information in the Chrysler service manuals has not proven to be accurate 100% of the time, but the slit in the rubber plug is quick and easy and will not hurt anything to check. The towing tilt sensor is also back there. It is possible that may be damaged from water. If the FOB locks/unlocks the doors and sets the theft alarm (blinking red light in the middle of the Tow-Away Alarm switch) and no water is found. Forget about that approach and move on. If there is water back there I would rectify the situation to be certain it isn't inhibiting the ignition.

Vipers approach is the way to go. I do not have the tools to check the CAN Bus comms