Just to update this thread:
When I was looking over this washer/dryer installation last week, in addition to not having a drain pan, I realized that there is no access to the water shutoffs because the washer and dryer are stacked. That means that if I have a water leak back there, I have to turn off the water to the entire RV. That's a show stopper.
I've got a voice mail pending with the Service Manager from the dealership but I'm wondering how others with the stackable washer and dryer are dealing with this situation of no access to the water shutoffs.