Great question! I've not come across that yet, but definitely something good to know. The only thing I could find is from the owners manual: "In the case of a dead battery, the tailgate can be opened manually. Contact your dealer or Roadside Assistance." Not exactly the most helpful 😏🤦♂️
They are available on the base Work Truck trim with the Convenience Package. I still have businesses that want the option to not have any power features simply to save money (and less $ to repair when their employees break things). That said, it's still available on every trim level.