Bungie is lame and got rid of noble's playlist and merged the noble maps with Defiant map pack and any other playlist, as long as everyone else has the maps, you'll be able to play Noble maps in most playlist.
Ya its complete BS. Which is why I well not buy the Defiant Map Pack. For just the sake of cause they might remove that when they come out with the next map pack.. I don't like being forced out of my own control do to something. This is not a communist