So the same just happened to me, however, I tried the save and load trick but Iorveth is still not showing up. This glitch really sucks because this has been one of the best if not the best sidequest in the game so far imo.
He often has valid points, it's just how he reacts to anyone who ironically disagrees with him that gets on my nerves, thinking that because he has exposure means that he is totally right and can never wrong.
By the way. The premium edition is a nice touch. It's almost as complete as what other games pass as limited editions - at regular retail price. Including a map and a krakenskull coin and a making of DVD and Papercraft and more..Almost like all games were back in the day before jewelcases.
Amen to that.
I've been quite busy today, so I have only played the first part of the prologue and I can say that I'm really liking the combat, can't say I love it because of some minor flaws:
-Geralt will randomly stop blocking attacks
-Magic takes a while to come out
-I'm not really liking that we can no longer drink potions in combat
-Combat can be quite challenging at times, to the point that I mainly used "hit & run" strategies.
Still, take in mind that this is just a really early first impressions from the prologue of the game.