Did Apple happen to open up Apple TV control with home kit?
A/V devices are not part of Home Kit. Lighting, Locks, Garage Doors, Thermostats are the current announced targets of Home Kit. It can be customized to some degree, but that kind of basic customization wouldn’t be used for something major like Apple TV. More likely, if Apple wanted to do something like that it would be a major revamp of Home Kit in a future iOS version.