Remembering that it's described as a custom chip its possible its basically Maxwell but may have some minor improvements that are also in Pascal. If they have stripped out the big/little arm cpu design and just left the big arm cpu's they have space to put something else, I suspect they may well increase cache to give full frame buffer size. Then how do you describe it when the chip is both improved on both Maxwell and Pascal in that regard.
Let's say effectively you have a gpu architecture that is 2/3rds Maxwell and 1/3rd Pascal how would you describe it? If your honest you would say Maxwell but then in doing so you negate the Pascal improvements. It's a custom chip probably designed between the mid-gen refreshe's of Nvidia's 2 gpu architectures.
What if Nintendo have designed it with full 3DS game compatibility for downloaded games not cartridges. Perhaps then there is a pica200 gpu in there too or part of the pica200 that not only helps run 3ds games but assists the main maxwell/pascal architecture for Switch games too.
When chipworks do a scan of the Switch main chip we may find it looks absolutely nothing like the Nvidia reference designs.
