Sorry I’m sure this has been asked many times but I want to be 100% sure of the answer.
If a buy an Apple TV for Zwift do I need a subscription of any kind to use the Apple TV itself? (apart from my normal Zwift subscription I use on my PC today).
Nope! I do exactly this. The ATV is effectively a screenless iPad/iPhone (with an older CPU) - it runs the Zwift app natively, and quite well.
You will probably want to use something like an Android smartphone to run the Zwift Companion app as a controller for the game. Not mandatory but it make interaction easier. (typing, changing camera angle etc) If you rarely to never interact with the game during a ride (beyond “riding”) you could skip that, or use the ATV Siri remote included with the ATV.
You’re probably confusing the Apple TV hardware with the Apple TV+ subscription streaming service. They are two separate things, and the latter is just an option.
I’m sure during the set up I had to authorise something on iTunes. Maybe I could have done that with a apple account but I didn’t have either, and the option, for me during set up, was to use iTunes.
Edit. It was likely to have been the app store set up. Not just zwift that needed authorisation