I am not convinced it won't work on multiple models. They don't actually provide a list of supported devices. The language here is unclear. At first, I thought

I am not convinced it won't work on multiple models. They don't actually provide a list of supported devices. The language here is unclear. At first, I thought it meant that this only was on the current Apple TV 4K, but then I thought it might just be marketing speak to get people to buy Apple TVs. But maybe the jump from the A12 to the A15 does provide something that makes this possible. The only thing I can think of is the neural engine (although that first debuted in the A11).