After having dealt with major floods recently in both my home and motorhome in the past 12 months, I'll offer some opinions for what they are worth.
Motorhomes appear far less impacted by water damage than houses. I am finding the leaky, plastic-infused walls and floors in an RV do not trap as much moisture as 2x4 covered drywall in a house. The only exception: the roof - where careful examination is very important. Not a big surprise, but I think there is a tendency to compare houses to motorhomes.
Bubbled floors and walls seem to be the biggest risk. Hidden damage? Careful inspection with a flashlight and moisture meter will make me happy. When purchasing my next MH, I'll look carefully for physical damage. I can then do a mold test if I think it is warranted. Test kits are under $20.