Does the door have to be closed to fold in the tent end, as this could be a safety switch to turn off the lights (if any) in the tent end. I used to have a TrailManor trailer (Mtnguy did too), that had a similar plunger switch that killed power to the lights so you couldn't fold it down with the lights on?
If the bathroom door has no bearing on the tent end, then my next guess is it being in the bathroom, that maybe it is a secondary switch to the bath fan. Don't know why there would be one, but you can see if the bathroom vent fan is affected by the opening/closing of the door. Maybe the vent fan sucks in the tent ends with the bathroom door open....or possibly produces vacuum pressure that makes the entrance door hard to open.
P.S. This reminds me of something you may not want to find out the hard way. If you have the bathroom vent fan running, and flush the toilet....... you may find out just how fast/much air those fans move , as it will suck the odor up right out of your black tank. Most people only make this mistake once (or twice in my case).