At E3 2015, we noticed a number of third-party headset adapters for the original Xbox One controller including the one bundled with the SteelSeries Siberia X300 we are reviewing. Microsoft probably won't state why it chose to not integrate the headset jack directly on the controller from the beginning though we can expect pressure from the competition as a factor for the refreshed controller. After all, the $20 official adapter as a separate addon was just another reason to go for the PlayStation 4...