I always got the impresssion that with "re-negotiating" his contract he got his freedom yes, but lost his immortality as well. So IMHO he lived a full lfe but died a bit over 1000 years ago.
I believe Jahan states that he'll live forever or something, I'll have to see if I can find a transcript of the dialogue.
Anyway I suppose it isn't out of the question for him to make a cameo although I wouldn't get my hopes up just yet. If he isn't in the game you'll have to make do with The Red Prince. He shares a couple of similarities with Jahan, namely that he's a noble that has to undergo a quest due to dealing with demons.
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