Having Warlord's bloodlust only functions against champions makes sense, but makes it worthless.
On PBE, Warlord's bloodlust only works against champions. This means that the crazy sustain it offers for anyone who can gets crits is gone, which was the only real reason it was good. (and broken on yasuo, trynd, and panth.)
Every other mastery effectively only functions against champions, so it's no surprise that Riot took it that direction. Still, unlike damage, lifesteal's main function is sustain against minions, not champions. Warlord's will need some compensation, either through removing the cooldown or through increasing its numbers just to see play, even on the champion's it's currently broken on.