If we're talking the A-Z HC Vol.4;
"After alteration by the Qwrrlln, Hudson possesses a computer-like mind, which grants him a photographic memory, incredible mental processing skills, and vast mental storage capacity. Further, his body has increased stamina and endurance, and can convert perspiration into electrical energy by means of an electro-osmotic reaction. Hudson can also control and override all electromagnetic frequencies once he has accessed their wavelengths."
So while definitely not human, not necessarily cybernetic either, but yeah I can see that the Master didn't completely revert him back.
The handbook is the only place after #130 that cybernetics are ever referenced though, yeah?
Not my words, just quoting the handbook.Also he never brainwashed him, they even state it a few times in #130 that he was never brainwashed. Even in #130 they state his computer like mind thought the Master's plan was logical and thanks to his cybernetic upgrade he listened to the Master's plan more and agreed.
As to now, best guess; Hercules was unaware of Mac being part cybernetic and revived him as 100% human *shrugs*