In an increasingly common practice, one of the two current-gen consoles are getting a favorable content deal for an upcoming highly anticipated AAA title. In this case it's the PS4 and Red Dead Redemption 2. The deal is pretty run of the mill, similar to the same one they cut in the case of Destiny. RDR2 players on PS4 will have access to future DLC earlier than players on Xbox.

This kind of deal has cropped up more and more frequently in recent years. One console gets some content or entire games earlier than the other, or some DLC remains exclusive to a given platform. While this may provide the players of the beneficiary console with an advantage, overall such practices hurt the industry as a whole, as well as the consumers.
While console exclusives are a necessary part of the industry to some extent, slicing up games and distributing those bits and pieces to different platforms prevents most players who cannot afford all platforms to experience the full experience. This is the whole "retailer exclusive pre-order bonus" that has plagued the industry for years made even worse.