This new ability doesn't make much sense to me. It's an instant active without downtime unless you've spent all the charges which is really only significant in PvE, when it comes to PvP you won't be using up all the charges anyway so it's not like the opponent can play around it. Barb rage, another instant active ability, you gotta time well and if you don't -- a minute of downtime in PvP is very significant for the enemy to take as an advantage against you, Ki Barrier on the other hand can be up for the whole duration of the PvP so it really doesn't matter when you choose to use it. If it was a passive nothing would really change, except your quickbar would look a little different.
So what's the point of it? Is it a coding limitation? Feels like a button to press just for the sake of pressing it with zero complexity attached to it and there's already so many active abilities these days it can become a bit overwhelming.