Are you allowed to leave the park once gates close? What if you are at a special event and will be coming back to the campsite after 8:00?

They give a code to get back into park

Yes, they give a code, so can in and out after the park is closed.

As the information that i have tells me that as a camper you receive a entrance code.

You get a code to get back

Campers get an entrance code.

Vehicles will not be able to leave or enter once the gate is closed.