From what I understand if you bought the game on Xbox during their game preview (when it was first released) or you were a kickstarter backer, you will be able to get the Dynasty Edition dlc for free. This will happen during the store's Thanksgiving sale, not sure when it starts, where you will go to the store and be able to download the DLC for free.
If that doesn't meet when / what system you bought it for then you will still be able to buy all the DLC for I believe $11.99. This is information I received in an email from the developers.