I think we knew there was custom silicon in Kinect 2 and we knew MS had hired a bunch of people from IBM and elsewhere for their internal semiconductor design group, but I guess we haven't had confirmation the new IC was designed totally in house.
It seems unlikely to me that most of the 200 people working on chip designs as quoted in the Bloomberg article were working on the Kinect sensor, especially given MS' purchase of 2 TOF companies prior to launching Kinect 1.0.
It seems likely that those other guys are involved in modifying the jaguar and VI chip designs.