I have never, to my knowledge, seen a "10 year rule" RV park.
I have seen "no firearms in your Rv" parks (I did not stay there). I have encountered "no more than 2 pets" RV parks (I did not stay there, either)
I have seen, and stayed in, military parks (no, not all of them are behind the fence).
IMO there is a difference between the "10 year rule" and the "We reserve the right...". It is very simple; the "10 year rule" is very specific. If I ever do encounter it, I will continue down the road. The "We reserve the right..." sign is general in nature. If they don't like the look of my rig, or me, or my pets, or anything else, they are saying they have the right to refuse to allow me to stay there. I agree with them, they certainly DO have that right, and I will happily get on down the road, as is MY RIGHT!
Their park, their rules. My rig, my money, my rules. When the rules and/or reality clash, I win. Everybody is happy.