I posted slightly too soon. tvOS now mostly packages, but at the very end signing fails with:
Provisioning profile "AgilePerception_tvOSCowboySmashProvision" has app ID "com.agileperception.cowboysmash", which does not match the bundle ID "com.YourCompany.CowboySmash".
That is definitely another bug, though, seeing as how I typed in the identifier myself:
