The cooldown on Koggy's new W is weird

For those who don't know, it'll have a six second duration and a seven second cooldown. However, the cooldown starts at the end of the ability rather than when you pop it. As far as I know, it's the only auto-attack steroid that works like that.

Was the goal just to prevent it from scaling well with CDR? Because otherwise giving it a 13 second cooldown that starts as soon as you pop it would accomplish the same end result while keeping how it functions consistent with all other similar skills.