Most likely true. But to me the answer for the question itself is not about whether the rule can be overridden by any other rules. It’s purely about the rule itself.
The intro supports this:
> You might know of some rule in your jurisdiction which overrides local rules, and allows certain classes of vehicles. Please disregard these rules; the park isn't necessarily in your jurisdiction. Or perhaps your religion allows certain rules to be overridden. Again, please answer the question of whether the rule is violated (not whether the violation should be allowed).
There is a difference between a rule being violated, and whether the violation of the rule is allowed. Like they say in that intro text.
Therefore, all of the examples with police motor vehicles and ambulance motor vehicles are to be answered as being in violation of the rule.