Does knock-ups count for the mastery, "Oppressor", ?

Don't know, but even if they would, bounty hunter is still better. It would only give you small early game DMG boost, while bounty hunter outclasses it as soon as you kill 3 different people. And with yassuo, it will be soon. It was made for tanks, people who usually don't take kills

Can someone confirm whether or not knock-up works for this mastery or not??