Oil pan eroded! Is this unusual?? on 2004 Jeep Grand Cherokee

Noticed an oil spot on my garage floor where i park my 2004 GC-"Limited" (8 cylinder). Barley 80,000 miles & no off road stuff.
Took into to the dealer as it was due for an oil change & filter. (I thought maybe the oil drain plug got "stripped")
Service Dept said the oil pan was eroded. ~$800.00 to replace it.
I am wondering IF the Wisconsin winters with snow & salty roads & car washes that advertise "underbody flushing" caused the oil pan to erode?

Asked by for the 2004 Jeep Grand Cherokee
Wisconsin salt will do that. Once the undercoating is compromised, vehicles in the northern states with a lot of salt on the roads during winter, will accelerate rust. So, this is definetly possible. Here's a DIY procedure if you wish :