The problem with this argument is, that it doesn't explain anything nor does it solve the hard problem of consciousness. You simply redefine consciousness to mean something experimentally detectable, and then use that to claim p-zombies are impossible. You can move on, but that doesn't leave the original problem answered.

"Consciousness, whatever it may be - a substance, a process, a name for a confusion - is not epiphenomenal; your mind can catch the inner listener in the act of listening, and say so out loud." That's simply a fact about human brains, and is of course empirically detectable, and we can in principle write out algorithms and then create a consciousness detector. That doesn't explain anything about qualia though, and that's the hard problem.