When are the lux buffs supposed to drop?

No clue, but the 'buff' in which if she kills somebody with her ult probably won't make much of a difference unless it worked like Darius' guillotine and you're able to make a mini light show by landing repeated ultkills. I think she just needs some better waveclear by either boosting the scaling on her E scaling, or allowing her W to proc her passive, perhaps with some bonus damage if it's done in that manner. Hell, even being able to apply her passive to towers with spells would be an idea.

At the patch release, like every buff, nerf, champ, and skin ever.