Well the other thing is how do you even make a smaller/cheaper Switch with the same 20nm chip? Like how is that supposed to magically work?
The current Switch is likely as small as you can have that chip without overheating, it's a hot chip. And we've seen teardowns now of the Switch, there's very little dead space in that design at all, it's considerably smaller than even the Shield Console.
And where are you saving money from to be able to sell it for any cheaper? The 2DS is cheaper than the standard 3DS because it loses the 3D screen, what exactly would a smaller Switch be losing? Those Joycons really likely don't cost anywhere near what people think they do either, once Nintendo gets past the initial cost of covering their R&D it's likely you're looking at a $2-$3 piece of plastic on both ends.
In actuality I think a very small version of the current Switch will actually come later rather than sooner, much like GBA Micro or 2DS (while not smaller it was basically the "kids version" of 3DS aimed at the budget market).
All other Nintendo revisions have either been the same price or more expensive than their predecessor.
To make a model any smaller you're going to need a chip that generates less heat. And that's really only possibly with the 16nm Tegra ... which likely means Tegra X2, Nvidia has already designed it and fabbed it out, it would be a pointless extra expense spending time on another 16nm design when Nvidia has already made a perfectly good one already.
