I don't disagree that it's very possible governors could order the parks to close again in a crisis scenario, but you better believe the parks will fight tooth and nail to keep that from happening. This dip back into 5-6% positive infection rate won't spur that.
Americans are by and large done with the lockdowns, conceptually, too, so even if the government forces more businesses to close and a resultant additional economic collapse, people will still mingle, still break isolation, still basically do what they want. I think there's less odds of a broad shutdown again than some here are theorizing, even if it means the virus spreads and inevitably kills more.
Test, trace, isolate isn't happening. The only other real scenario is to limit personal risk and keep hospitalization rates in acceptable parameters. Otherwise... expect stuff to stay open.