The ban system for OWL and for Ladder play is entirely separate and we’ve known this from the initial announcement. It only makes sense, as the two systems are very different in terms of who is playing and how players decide what heroes they’ll play.
Hero Pools on ladder is not punishment. It’s to improve the experience by weakening the grip meta has (particularly on higher ranks) on hero choices. People want more varied games and this should do a lot to achieve that. Personally I suspect it will only be implemented at a certain rank barrier, as I’ve seen constant complaints from non-GM players about the system.