I really don't think Ahsoka's fate (or anything else in The Clone Wars for that matter) is going to change because its now owned by Disney. Filoni has confirmed every story has come directly from George himself including Ahsoka's fate and I don't see them deviating from that.
Personally I really hope Ahsoka dies and it has nothing to do with the fact that I can't stand her character I simply think it will make a better story. I hope she dies and either she dies saving Anakin, its Anakin's fault or he blames himself even if its not his fault. I think adding the Anakin element to her death will only add to fuel to Anakin's downfall in EpIII.
If she doesn't die then she'll die in during Order 66 or the Jedi Purge if they're sticking to Lucas's intended version of the prophecy of the chosen one, and as Ahsoka is a Lucas created character I think they'll stick to it in her case. I know in the EU quite a few Jedi survived the purge but Lucas has said himself his intention was for Vader, the chosen one, to kill all the Jedi except two (Obi-Wan and Yoda) thus bringing balance to the force by having only two Jedi and two Sith.
As others have said it was the Dark Nest trilogy were Luke finds hidden recordings in R2's databanks that show some of the events of EPIII including Ankain and the 501st attacking the Jedi Temple, Anakin causing Padme's death and Padme giving birth.
There's also a novel called Tatooine Ghost where Leia travels to Tatooine, meeting Kitster and finds Shmi Skywalker's diary which gives her information about her Father, Grandmother and the events of EpI that take place on Tatooine.