Dunno why, but it is. If you don’t already have it, go git it.
Direct link: http://marketplace.xbox.com/en-US/games/media/66acd000-77fe-1000-9115-d802434307e1/?did=0ccf0006-0000-4000-8000-0000434307e1&bt=0&sb=1&mt=4&gu=66acd000-77fe-1000-9115-d802434307e1&p=1&of=6
This is for the 360 only. It added to my DL queue without deducting MS points, so it seems legit.
Feel sorry for anyone who ever bought that, what with it being free with the collector’s edition and now free altogether >_>