They could’ve dumbed down the CPU explanation into something as simple as “the human mind is creative enough to make connections robots can’t conceive of, so the machines need us to build new patterns to sustain the matrix” and that would’ve been enough. At least it wouldn’t violate the laws of thermodynamics.

Also I heard it wasn’t the Wachowskis who wanted the change, but they got pressured from some suit who said it was too complicated.