I don't think so. Back in classic edition, I was confused by the exchange with Zaleskar. I was under the impression that he was essential for the quest, but I remember that talking to him didn't really reveal anything. I had only two or three dialog options (Sebille-specific) and all of them led to a fight with him, because he refused to reveal anything, and also refused to be intimidated.
Later in Act 2 you will eventually learn more essential info from a guy, then you pick up from there. So I think you should be fine.
EDIT: After a bit of checking in classic edition, there are several persuasion options, but my Sebille had no persuasion capability whatsoever, that was why the conversation always ended in a fight, without revealing any info. So I'd say the entire Griff-Zaleskar portion might as well not exist, and you'd still be fine.
Last edited by Try2Handing; 23/09/18 05:57 PM.