No actually it isn't and hasn't been. Chaos Space Marines are a separate +35 point upgrade that adds +1 leadership, shifts the ship's (and commander upgrade's) leadership to a maximum of 10, improves boarding actions and hit & run attacks, increases planetary assault points, and depending upon the fleet list might also allow you to swap attack craft for thunderhawks and open up access to Marks of Chaos for some fleets.
This isn't included in the Chaos Warmaster/Lord upgrade (you can have human champions of chaos and not just traitor astartes) in the Armada book 13th Black Crusade list (nor the BFG:R lists), but is a separate purchase per ship.