First of all, can we please stop this 16TF nonsense?
Vega64 is a 7nm chip. It is expensive as hell. It burns 300Watt. It isn't even close to 16TF. Thinking of designing a 16TF vega64 is simply impossible, end of story.
Anybody who thinks they will get a 16TF console should go see a doctor, seriously.
Secondly, the "Two XBox models" - I don't see that. Unless Microsoft is willing to lose a shitton of money on hardware. Having two SoCs means double the development costs (and designing a 7nm chip is NOT cheap). It also means taking care of two supply chains, not just one. again, very expensive.
My guess is we'll see something like a 54CU 1200-1400MHz console, no more.