Microsoft has officially delivered the coup de grâce to the Kinect. Even though the Xbox division has placed an increasingly diminished emphasis on its motion control peripheral in recent years, the final step in separating entirely happened today.
Microsoft confirmed to Polygon that it has ceased production of the Kinect USB adapter. This device is necessary to use Kinect on Xbox One S and Xbox One X models. Only the original Xbox One featured a dedicated Kinect port on the back of the machine; the console revisions only have standard USB ports that require the adapter to use Kinect.
Because of the port changes, Microsoft ran a promotion through March 2017 where it offered a free Kinect adapter to anyone who had an original Xbox One, a Kinect, and an Xbox One S. For anyone who didn't meet that criteria, Microsoft also sold the adapter at a price of $40. However, as Polygon notes, it hasn't been available for months now. The only means of acquiring one is through third-party sellers, and most of them are asking several times the original price.
In the confirmation, a Microsoft spokesperson told Polygon "After careful consideration, we decided to stop manufacturing the Xbox Kinect Adapter to focus attention on launching new, higher fan-requested gaming accessories across Xbox One and Windows 10" and added that the adapter "will no longer be available." It's less of a surprise and more of an inevitability. Still, long time coming as this was, today is the day we have final confirmation that Microsoft has divested itself entirely of Kinect.