The Living Tribunal is the overseer of the Marvel multiverse, which includes 616 and all of the other realities within it. Considering that we've had a theme of the timestream and realities breaking down thanks to Age of Ultron and the stuff going on in Hickman's Avengers books, as we speed towards Infinity and Cataclysm, this doesn't surprise me that he would pop up.
Hunger #1 really surprised me with how good it was. Rick Jones! The Watcher freaking out, and the merging of Gal-Lak-Tus and Galen!