From what I know, they did patch to fix it and players just found another way to exploit and use it anyways. Ubisoft asked the organizers not to allow that "tech" to be used but the organizers decided to allow it anyways.
Also this is the patch coming out tomorrow.
"NOBUSHI
Unlock tech
[Bug Fix] Cobra Strike and Sidewinder Form can no longer become un-parryable if unlocked at the right time.
Developer comments: There are a number of situations where unlocking during an attack can cause it to become un-parryable by the opponent. Across the game, weÂ’re currently working to remove this unintended behavior."
For all those saying Ubisoft don't care, the team responsible for the game has had weekly updates to address issues. I've been playing since release and yeah, there is still things in the game that need fixing, but they are constantly doing more for the game.