In all of the XY sets we have goten cards of all of the pokemon featured on the pack art. Why would it be any different with Hoopa. In XY we had Yveltal, Xerneas, M Blastoise, and M Venesaur. In Flash Fire we had M charizard Y, M Charizard X, Pyroar, and M Kangaskan. In Furious Fist we Had M Herocross, Hawlucha, Tyrantrum, and M Lucario. In Phantom Forces we had M Manectric, M Gengar, Aegislash, and Diancee. In Primal Clash we had P Groudon, P Kyogre, M Gardevoir, M Aggron. All of which had at least one card in their respective sets.
Roaring Skies follows the trend as well with M Rayqueza, M Gallade, M Latios, and Deoxys all featured on the pack art and included in the set.