I have done Briskets wrapped in foil, butcher paper, and naked. All produce different amounts of bark. In my experience cooking without wrapping gives you the best (firmer) bark. Using butcher paper is a nice mix between foil and naked.
I suggest you cook the brisket you have in your freezer. Cooking Prime brisket is great but not the end all for great briskets. I have cook many great Choice, Prime, and Wagyu briskets before. One of the best briskets I ever cooked was a choice brisket I got from Walmart.