I don’t really buy it. Whatever the storytelling style, and whether or not it changed midstream, there were satisfying ways to end the story that would have been self-consistent, doing justice to the characters and remaining true to the overall themes of the series. As near as I can tell, the explanation for why we didn’t get such a denouement was simply haste, laziness, and literary incompetence.
ETA: I understand that the things I complain about could be seen as resulting from the change in style that the article posits – I just don’t think it’s necessary to explain what happened, and that the actual reason is simpler.