Dunno what type of RV they're traveling in. Personally, I think there's a minimal risk to truck stop overnighting if you're in a class A, B, or C where you can go between living quarters and cab without going outside. There's maybe more risk in a towable or TC, but I have no idea of how much more.
I've stayed in a lot of truck stops, rest areas, and a few WM's, but I'm a solo traveler in a 19 foot C that fits in the car spaces. I actually prefer truck stops. WM's are quieter on the average, but there's always the lot sweeper or a jasax with no mufflers at 2 am. Trucks stops tend to be at a continuous low roar, which I can sleep thru. But I do carry throw-away foam earplugs in case they're needed. I keep my wandering around outside to a minimum day or night, and look around before opening the door.
Jim, "Mo' coffee!"