Its confirmed
Spoilers for the film... obviously.
Neji and Karin were killed specifically to make NH and SS happen. It all makes effing sense now.
I suspect they and the rest of taka are being offed because he doesn't know what to do with them and they have no obvious place in the uncoming series. They've never really had a place in this story, and I am not sorry to see her go. Do feel a little bad for her fans that she is basically pairing fodder for SS and that right after she died Sasuke claims to have loved Sakura from the beginning.
So, it suddenly turns out Salada is part of Karin's name and that's where the name of their daughter comes from. Fantastic. So, when Salada asks what made Karin so special Sasuke should say, well, I tried to kill her once and I needed to honor that memory. God, Karin is such an awful character.
Totally making kitten up as they go.