Does this incarnation of AirPlay perpetuate the ability to play through an AirPort Express Base Station? (I assume that a yes answer would confirm the continued existence of AirPort Utility.)
Just to put your mind even more at ease Airport Utility is now Universal code. (By-the-way I still rely on an Time Capsule and three Airport Express units to support a 2.4GHz WiFi network for HomeKit devices that don't play nice with 5GHz or Mesh networks, so I am interested too.)