If you read the contract it says it was going to be made for next gen back in 2010ish it calls the Xbox xbox 720 lol but later it was rewritten. It was probably originally for Xbox one but when they saw the PS4 specs and Sony made the bid for content they took the deal and it was easier to develop games on it. Xbox has more glitches and stuff in the game because it is a port. Technichly it was going to be Xbox as the main console, and it was only going to be next gen. Ps4 is faster to develop on and time is money so in the end it was the best choice. PS4 was also the favorite to win the console war and they did. Why the game is on last gen consoles is to increase sales, however that was a last moment decision. The race to port all the content and distribute it unilaterally meant They had to redistribute man power away from next gen to oversee contractors. See the game credits and note all the contractors. Basically they did not think there would be enough next gen consoles out by the time the game hit the market based on console sales after E3 2013. So now they have to spend extra on advertising more and finishing work that should have been complete if not for those final changes.