I don't think it does, cause I didn't still get one of the girls from 2 of trolls, and I spent over 2k fights on one of them and close to 600 fights on another with quite a lot of those 600 being since they said about that 3x times drop rate for event girls.

I needed on most events before from 8 to all 14 event days to get lucky and get both event girls, with this event 3x buff i got both on like first day.