In fairness to Jordan, the only extraordinary delay in the series was due to his actual, you know, dying. So far as I know he never had a creative delay like Martin's infamous problems writing DwD (one article I saw called it the "Chinese Democracy" of fantasy books). I really think he's done with the Carpenters (except maybe Molly & Daniel), Maggie, Mouse, the Alphas and Thomas & Justine for the time being (at least regarding any major advancement of their characters or arcs), hence the little "happy-ending" vignettes we were shown.

I also think I should clarify, having just finished the book and with the disappointing wind-up still fresh in my mind, there was also some good stuff in it. The flashbacks of his time with Justin & the fight to escape him were good (and their existence supports your theory in my opinion - from stuff I've read in interviews and such that sounds like the kind of material he might have already had written, even if only in outline or rough draft form, whether for his own character-reference or as short-story material or some other sort of filler. It really seems like more padding in the book, with the goal of stretching a reboot into a whole book to start fresh. In my opinion, I don't think it was all that necessary, since he could have simply moved on from where he left off before being shot, without inserting the deleted-scene flashback from Changes.

In my opinion the character changes/growth experienced in this book was kind of redundant, unless it was to service his issues with what he did in Mexico. All that stuff about Uriel needing to tell him the words to balance what the Fallen had whispered to him was not needed, since he had already come to the same conclusion back when he accepted Mab's deal. Most of his development in this book was effectively a kick in the pants telling him to stop being such an emo-whiner and get on with it. I hate that crap where if you knock off a bad guy, you're responsible for tertiary consequences that are the cause of the bad guy's actions and not yours. tDF is usually rather on the money when it comes to the moral and ethical issues, so that stuff about the power-struggle following the fall of the Reds being on his head is annoying, since I have come to expect a more mature outlook (and issues of moral responsibility aside, he heard it straight from the Merlin's lips that the Council was going to do the same thing anyway - Harry just spared a lot of good guy casualties and collateral damage: the power struggle was bound to follow). But the other bull crap, like it being Harry who ordered his own hit - come on! Suck it up, and stop sniveling. Talk about your responsibility for power vacuums! Had he just gone along with Mab, there would have been far fewer rumors about his unfounded demise, though anyone with any eyes-and-ears in Faerie would be aware that the big, scary Dresden had just gotten an upgrade. So the strife in Chicago IS his fault in a way that the Red Court's fall is not.

So with all that kind of ass-backwards moralizing and whining, the characterization was a bit of a disappointment, but hopefully this is his "getting over it/PTSD" phase regarding what he did to Susan. All in all, I'm eager to move on to Cold Front or whatever the next book is.