The issue with the auto-parry is that he has to be in neutral -- which means he can't be blocking, so anything else gets him kicked in the face. It does stop a lot of characters punch strings, which is more important in DoA than it is in VF.I just tried this in training mode. Set opponent to just do high punches and just watched Jacky auto parry. What a fucking bullshit move!
Just be happy that his 3K+G~G (which is think if a different command in DoA5 -- something like just 6K~G) doesn't take off nearly half your life on NH in this game, like in can in VF! His dumb throw throw OS with that move (where you do the startup of the kick to avoid throws, and then guard to block attacks) still works, though. -_-