Besides the Tegra X2? You know, the Pascale based Tegra that's more effecient than even Mariko? Or a customer made Xavier? Xavier has tensor cores at that which could help immensely with AI programming, and shaders. Weird everyone here isnt even thinking of that, just overclocking the current chip.
And the Tegra X2 is not suitable to gaming like the X1 due the different ARM processor.
So nVidia needs to do a gaming sucessor to Tegra X1 but right now there is none.
Of course Nintendo can ask to nVidia create a new Tegra chip specifically to Switch Pro but nVidia will ask tons of money todo that (that is the reason Switch used X1... Nintendo got a great deal to buy the non-used X1 that nVidia had in warehouses).