Hunter special is a common end game but probably not the majority.
I suspect a lot just wind up in back yards/farmers fields rotting away until the house get's torn apart and goes to the land fill. The frame and running gear would likely be taken by a scrap yard.
I do wonder if scrap yards favor aluminum sided over fiberglass. Scrap fiberglass siding has no value. The aluminum is quite valuable.
Depending on the damage, there probably is a market for a lot of the hurricane RV's appliances. If the flooding went say 4-5' deep, the floor is probably trashed but air/con is probably fine and the stove and fridge might be fine depending on how high and for how long the the flooding went. Furnace & hot water heater being down low likely won't fare as well.