Okay, so those of who have completed Halo 4’s campaign know that after Del Rio abandoned Chief on Requiem, he was dishonorably dismissed from control of the UNSC Infinity. He was dismissed with good reason, as he was an irrational, ill tempered, and brutish leader. Had he heeded Chief’s advice, the Didact probably wouldn’t have been able to assault Earth.
But is this really the end of him? Dismissed does not mean completely discharged from naval command. I doubt the UNSC would allow for that to happen. After decades of genocidal war, it’s a time of growth and repair, and the UNSC will want everyone who can provide a valuable service. Let’s face it, despite the fact that he’s a jerk, he initially got there for a reason. And this might mean he’ll play a role in future Halo fiction (like Halo 5, as an example).
So what do you think will have happened to him? Also do you think we’ll learn more about his character, as well as why he seemed so vehemently antagonistic towards the Chief? I’d say that he may return for Halo 5. After being demoted and having his reputation damaged he’ll probably want to enact some kind of revenge on John, and as such he may the role of a minor antagonist within the game.