I disagree, because CSZ can use that parry just once to make Sub think twice about pressuring him. And CSZ has his own decent corner-pressure. Besides, CSZ doesn't have to go for block-strings after teleporting, he can always throw, or low, or mix up in other ways.
It's at least 5-5 in my opinion.
Parry can be baited fairly easily, so Sub getting hit with a Parry isn't necessarily a bad thing. After getting hit by it once, Sub can show pressure and bait it and go into full combo.
And as far as teleport goes, I still think you're over-estimating its speed. In all practicality, it is an anticipatory punishing move, not a reactionary one, and it's most definitely not a mobility tool. If you hesitate for even a split second, chances are Sub's Ice Blast will freeze before Cyber Sub can even get off screen.
Also, Cyber Sub is one of the few characters that has no consistent way to escape Sub's corner pressure. Teleporting is probably the best option, if he can actually get off screen, because most likely he will only be punished with a poke or a smaller combo (he is in an airborne state when appearing on the other side). Cyber Sub possesses no armored moves outside of X-Ray, so a well-placed clone into 22 pressure literally locks him down. So, let's recap. When trapped in the corner: Cyber Sub can use 3 bars of meter (if he can even get into the air to perform X-Ray in the first place) or he can eat about 23% (if the Sub player properly does 224~Slide or something of the like).
I see no instance in which this is 5-5. Among two equally skilled players, the Sub-Zero will win the majority of matches. In my opinion, it's 6-4.