Again, it's not healthy to joy of something being taken away, but this one isn't much of a big loss, really. I'd just rather put Shatter from WotOG packs into the deck, burst dmg spells will do the trick without IL combos anyway.
Most warlock zoo decks I've encountered never carried PO with them nor does current meta supports using it anyway. Though it IS part of Leeroy and probably number 1 reason to rotate it out of standart but, e-e-eh, it's only 20 damage on turn 9 at best, you have to do 10 dmg first somehow too. There's not much to like when something's removed but not the biggest issue, unlike Azures. The loss of Imp Gang Boss and Dark Peddler more hurting.