As you mentioned, when the scions "disbanded" He did say he was going to check out the new world or Meracidia if you talked to him through optional dialogue. I thought we were going to see him in Dawntrail when it was announced, since Tural is one of the places he might conceivably go to, but it seems that was for naught...
For someone without any speaking role he's had an absolutely massive impact on the story.
He's the guy who gave us directions and advice on how to fight Titan. He's the guy that caught wind that something was going on with the Crystal Braves and warned us that something was going to go down prior to the bloody banquet. He's the guy that helped us take down what remained of them. He's the guy that became the eyes and ears of the scions, and is the source of almost all the information gathered from Garlemald and around the world from post-heavensward onward. When the started popping us, he was the first to inform the scions of the tower in Garlemald. And there's oh so much more. Like if you talk to him with optional dialogue whenever he's around you'll find out just how much involvement he's had with everything behind the scenes.
I can't think of a single unvoiced character that's had a bigger impact on the msq, personally. The writers have got to give that man a voice!