I don't think there will be any flashbacks. But I think the impact her journey had on her was that she finally realized that a life with Christopher is not an option. That was something that would have stood between her and Luke for the rest of her life, as it had already caused trouble when L and L were still an item. In any major crisis (as they naturally happen in marriages) she might have fallen back into Chris' arms, just the way it had happened to her many times before. That's why I think this was necessary, so that she could rule out the "Christopher - Marriage - Alternate - Universe - Option" forever.

and I agree with you blaab.

first I don't think Lorelai was ruined at all in any way. and especially not by Rory's independence. In addition to that, I totally understood why Lorelai went to Christopher after the blow up with Luke. It was weak that she slept with him, but to err is human.