There's no reason why a Wii U processors (CPU & GPU) can't be included as part of an APU as a separate chip from the main one in a similar fashion to how Sony uses an ARM chip for their background downloads.
Maybe instead of having an MCM (Multi Chip Module) like Wii U does now, Nintendo gets a partner chip maker to design a single APU, that includes all of the technology on Wii U's MCM, but builds it into a single die, thus making for a simple part that can be installed on the motherboard of their next console.
The Wii U APU can function like PS4's ARM chip, while also handling backwards compatibility with Wii U and Wii games.
Being that Wii U's processors are made on 40 and 45nm fabrication processes and we'll be moving to 14nm in the not too distant future the energy requirements of such a chip will be miniscule, we're talking roughly a 3rd of the power consumption of Wii U's current chipset, likely less than 10 watts.
Failing that Nintendo could just make Wii U's CPU and GPU a part of their next console's APU.
That's what I think "absorbing Wii U's architecture" means.
Personally I hope Nintendo gets off this whole "must use virtually no power" kick they were on with the Wii U's design. While it makes for a low energy bill, it absolutely stunts the system's capabilities compared to what's possible with a little more energy.
I hope they decide to go with around PS4/XB1 levels of consumption for their next system.
Both of those systems are pretty cheap to run, very cool and with silicon getting much smaller it just increases what's possible from a developers POV.
