No. That person is wrong, and the government body that regulated these things would be pulling every Caravan with a trailer over if there were issues.

I've pulled 7K lbs with my van.

I regularly pull 1000lbs.

8-10 times during summer I pull a 3K lb camper.

I was rear ended by a Caravan who failed to see a stoplight. They were going 40-50 KMPH. My van sits higher in the rear due to my airbags, they hit my hitch mostly, pushed their rad into their engine, almost no damage to my van and my hitch is where it was the day I installed it.

Moral of the story, the steel they use for the frame sections in the unibody are boxed and strong. You don't need 1/8" steel to be safe, even 18ga is safe for this.

I always leave it in OD and I even use the A/C when I am towing. Modern vehicles don't have 1/10 the problem older vehicles did, these Caravan motors don't mind revving up when needed as well.