Well partially what he told you is do do. That's the part about jeep
The real deal is it's always been necessary to retorque mag wheels after say 100 miles on all cars. It's in your owner's manual. But people don't read that little gem and a wheel might fall off. Then it's a blame game. So the tire store must have been sued because of a mag wheel comming off a customer's car. I'm on a travel trailer group and people have started putting on fancy mag rims and a couple have lost wheels and the game starts. "They didn't know they needed rechecked"

My crd's wheels don't have corrosion on them but the ones on my 00 XJ (cherokee) have some on the inside where they meet the brake drums/discs. It can happen on new wheels or corroded ones.