It's no secret that Ubisoft and Microsoft struck up a deal when it came to The Division. The beta for the game was made available a day early on the Xbox One and the DLC for the game will be available in advance exclusively on the Xbox One, yes that includes the free DLC
Details on how long the DLC would be exclusive to the Xbox One had yet to be revealed, until the game retailer GameStop put up a video, featuring Microsoft's Larry Hryb, declaring how great The Division will be (specifically on the Xbox One – obviously sponsored by Microsoft).
According to one of the individuals featured in the video, "Content on Xbox One will be delivered 30 days before Sony will see it."
The guy says it at the 1:45 mark.
Thank you, All Games Beta.