Well it certainly hurt AD and On-hit Lulu. Looks like I'll finally need to pick up AP/AS Lulu. I'm excited to try it out.
AD was always inferior. Similar damage, worse utility.
I always preferred kind of a tanky on-hit build. I guess I avoided AP/AS Lulu since her passive didn't scale with AP and I preferred the extra durability, but with these changes I think AP/AS is finally clearly a better pick. It was more of a matter of preference/playstyle before.