If I were pulling into a park and someone wanted to meet the dogs I would have no problem.... with those dogs that are social. Since I have two these days that are not reliable around strangers (both under twenty pounds), if you said "bring the dogs in to say hello!" that's the point at which you'd find out that not all dogs in my household are friendly.
Ninety percent of the information you'd need you'd get right there. The rest when the dog walks in. Yes, there are plenty of dogs around rv parks and yes, if you have a dog social dog and you own or run a park, there's no reason not to have that dog around. Again, you're going to get most of the information you need long before any dogs need to physically meet each other. People may act stupid, but they aren't so stupid that they don't know their dog can't walk up and meet a human or another dog without an issue.
And when someone looks at you and says "uh...." with that look on their face, or even walks in gripping the lead like that dog is going to eat someone, you'll know. Dog expertise NOT required.
Can you always account for every single thing the dog may encounter? No, that's not possible. But you can certainly weed out vicious and unstable dogs of all ages and if I were running a park, I would want to meet guests' dogs long before other guests had a chance to.
As for OSHA, maybe you're not aware, but there are kennel attendants, vets and techs, groomers and trainers and for Pete's sake the people that work at the local pet store that regularly meet strange dogs in the course of their working day.