I'm backing Filoni on this one. The good news is Lucas known for changing his mind. As long as she's not dead in the "already filmed" episodes that haven't aired, we have a chance that she will live on. If Lucas is out of the daily business of Star Wars now, Dave might have final say, unless he's going to bend to George's wishes, but that would be just out of respect and not because George is the "boss". Also I don't think they would go through with this dramatic of an ending just to kill her off in a few more episodes. She would have just rejoined the order and died some other meaningless death before ROTS. I think Dave may have wont the battle of if Ahsoka lives or dies.