They probably should have called the WiiU the Super Wii or Wii 2 or something, but on the whole they've got a mostly coherent naming convention.
nes:snes = 6502
n64 = mips
gamecube:wii:wiiu = powerpc
switch:switch2 = armWii is a game cube with a funny controller. Or, wii is a tv-only olde switch.
I appreciate that it has its own name due to being a transitional experience.