Death has already been cheapened rather significantly in FFXIV. I don't think it'd be a good thing for yet another character to return from the dead - especially since it was stated that 3.0 would be a darker expansion. If anything Ratatoskr returning from the dead would make things worse because the countless Ishgardians murdered by the Dravanians would not return from the dead. Realistically that would just breed contempt and spark a fresh conflict. In fact, I'm actually hoping that we don't make peace with the Dravanians. None of them have come across as particularly likeable to me - unless you count the more minor dragon NPC's out there.