Nope, the Iphone 6s has about the same. Here's how I did the math:
Does the iPhone 6 actually have console-quality graphics? | ExtremeTech
The above claims the 5s GPU has 115 Gflops, the Iphone 6 is 50% faster at 172.
The Apple iPhone 6s and iPhone 6s Plus Review
This claims 90% performance improvement for 6s, with 12 textures/clock. Also provided was the number 115.2 GFLOPS at 300 MHz
So I estimated Iphone 6s fpu performance at 172 * 1.9 = 325 gflops
I used that to estimate the iphone 6s clock speed at 300 MHz * (325 gflops/ 115 gflops) = 850 MHz!
Now we can compute the texel rate a 12 per clock cycle = 10 Gigatexels/s
And here is the Wii U specs:
TechPowerUp
8.80 GTexel/s
352.0 GFLOPS
Looks pretty close to me. So no, the NX wouldn't see an upgrade at all. And that's assuming you know your way around silicon wizardry like Apple, not the half-assed patchwork Nintendo usually does!
Hasn't there also been serious tumors the platform is now x86. Which pretty much leaves some junk Intel tablet processor. Maybe wiiu caliber graphics and another crap controller.
Sony and Microsoft have VR, Nintendo has another dumbass tablet controller.