Presumably you won't be plugging your tent into any of these common North American RV dock connectors:
- 240V/50A on a NEMA 14-50
- 240V/30A on a NEMA 14-30 or
- 120V/30A on a "TT30"
In those cases, they provide a ground wire, and that is tied to the vehicle frame. AFCI/GFCI is provided via branch circuit breakers inside the RV's own distribution panel, at the discretion of the RVer. If the RV campsite didn't have ground, they wouldn't be allowed to install the above outlets, and RVs couldn't plug into them. Ground is not hard to get at a campsite, in fact if the electrical connections are made via underground metal conduit, practical grounding is a done deal.
On a tent, presumably you will be using the common electrical outlet that is universal in North America, our old friend NEMA 5-15. Any outdoor NEMA 5-15 (or compatible NEMA 5-20) must be GFCI protected. NEC 210.18 in the US.
In residential, there is a long tradition of grandfathering previous work that was done to code at the time it was installed. This is merely to prevent every homeowner from having to hire an electrician every 3 years, and the concomitant "boom and bust" cycle which would be very bad for the profession.
However, enforcement is up to local authorities, and they apply a sensible view on grandfathering. Grandfathering is less allowed for a commercial operation -- more for sites with internal electricians like auto assembly plants, and less for public-facing operations. And far less where the urgency:cost ratio is fairly high. Slapping a $20 GFCI receptacle at a campsite stand isn't a big ask.
So I would certainly expect any campsite that is inspected to have them 100%. When is the last time you've seen a public bathroom without GFCI on the receptacles? (test/reset buttons, or sticker).