Regardless if that guy had Covid or the flu, I think it is just plain inconsiderate to be knowingly spreading germs. I don't like to get sick, whatever it is! If I had the flu, I would certainly not be out socializing!
The RV parks are just like the general public. Some take precautions and some act the same as pre-pandemic. I've been to RV park offices that had set up no contact check-in....and to some where I've gone into their small office with unmasked employee and several other unmasked RVers waiting to check in or just socializing.
I also do everything I can to keep myself safe. You have to set your own boundaries. I've literally had to back up from some people who get what I consider too close to me to talk. My friend was in an RV park laundry room and she had to open a side-swinging dryer door just to get a guy to stay a distance from her.