All her VA confirmed was that she always knew this would be Pyrrha's fate, and no mention was made that she would never voice Pyrrha again. Now I don't believe she will be brought back, but I can see some flashback and/or Guiding voice type of thing, especially how in Joan of Arc's legend she claimed to hear the voice of God and that guided her through her many trials. Besides, even if that type of thing wasn't planned form the beginning it can always be incorporated later. Again, I do not see Pyrrha returning to the land of the living but her role in RWBY I feel is not over quite yet.