That comes from a Q&A session at one of their appearances. Apparently Gordon confirmed it will be a thing, and Ilona gave him the Look Of Death. I had no clue, but someone evidently spotted something in one of the earlier books that made them suspicious, or else they were just speculating wildly.
I agree that Julie did not handle it well, but she is still a teenager who had a very rough start to her adolescence including the loss of her parents, and Kate, bless her heart, is not always the poster girl for effective communication skills herself. In particular, when they were over in Europe, Kate was kind of an idiot IMO. I cut both of them some slack, because Lord knows I need people to cut me some slack sometimes. And I am homing in on 60.
I'm not fond of Saiman and wouldn't miss him all that much, but he is half Aesir, and they're hard to kill permanently. Specifically, Kate has deduced that he probably descends from Loki. Most likely those who miss him won't miss him for long. From my perspective, he has progressed to doing the right thing of his own volition, though for the wrong reasons, so there is hope that he may evolve further. Before this I just considered him a garden variety sociopath, and I have had enough exposure to those that I don't find them particularly amusing. I've had even more exposure to teenagers, of course, and they generally do evolve eventually, much more frequently than sociopaths do. Hence my patience with Julie.
