The reason I believe T239 is made on TSMC 4N is the same reason I believe it was always intended to be made on 4N: it's simply too big a chip to work in a Switch-sized device on Samsung's 8nm process, drawing somewhere around double the Switch's GPU power draw at the lowest possible clocks. If I, a random internet person with no specialised knowledge in the area, could have said years ago that 12 SMs would be way too big for 8nm, I can't see Nvidia getting the whole way to taping out the chip before scrapping it and replacing it with an otherwise identical TSMC 4N version.
So you agree with the conclusion that Switch 2 won’t be on S8N given the size of the chip (as I do) but you’re reaching it from a different perspective?