I think there is another aspect or drawback to Murphy's death that hasn't been mentioned. She was the major vanilla mortal in the series. Yes, Michael is still around, but he played for one of the big teams in the supernatural world, so he doesn't have an outsiders perspective. For the same reason, Butters and Sanya aren't vanilla mortals. Plus, as Molly seems likely to go more Wintery, Michael; and for that matter Charity, may have their own concerns to deal with and become less helpful to Harry. As odd as it may seem, IMO the Alphas are now the closest characters to the vanilla world, because outside of their shapeshifting they mostly lead vanilla mortal lives. However, it's questionable how much we will see them in future books. Seeing as the next book will deal with the next year in Harry's life, it would be natural for Harry to have at least one conversation with Billy and Georgia, but I'll be surprised if they play a major role in keeping Harry grounded, but to a degree they've played that role before.
I suppose this could also be a good thing, depending on the quality of the writing of the rest of the series. Except for raising his daughter, Harry is now fully immersed in the supernatural world. Of course, the possibility exists that Maggie will soon be spending a lot of time away at school (Yes, I know some of you are really hoping that will happen.) so that reminder of something beyond wizards, monsters, angels and demons could get pushed further away. Maybe the idea of Harry getting pushed to the dark side or Hulking out, has something to it.
Earlier, I stated that I felt that Murphy had been indifferently written; as a more polite way of saying poorly written, since Changes. The larger truth; and others have brought this up, is the series since Changes has been uneven, at best. For the record, I really disliked Ghost Story, thought Cold Days dragged quite a bit, liked Skin Game; though it was far from perfect or as good most of DF file books between 5 and 11, and I wasn't impressed with either Peace Talks or Battle Ground. However, that doesn't mean I hated Battle Ground. It did just enough to make me want to read the next book, and probably the next book after that. (I guess I'm really looking forward to Mirror Mirror.) One good thing from Battle Ground is; and I didn't think about this until recently, I'm really glad that Harry has been kicked out of the White Council. Within the story, the characters who pushed Harry out think they have weakened him. I think it will backfire and Harry will become more powerful as he is forced to make alliances and negotiate with the heavyweights within the supernatural world. Though Harry still has to worry about crossing the Council or openly breaking the Laws of magic, he doesn't have to answer to them either. From a readers perspective, this could be really fun. I also like the forced engagement to Lara Raith, for pretty much the same reason. I think many readers focused on Lara Raith as a possible; make that impossible, romantic partner for Harry and reacted against that idea. The fun part of the engagement is; or IMO should be, how it forces Harry to interact with, and learn from, the many interested parties who will be watching Harry and Lara.
So, that is why I'm not one of those readers who is ready to quite the series. That said, I think a lot is riding on the next DF book, and probably Mirror Mirror as well. I don't think I'm alone in this, a DF adventure set in the world of professional wrestling doesn't hold much interest for me. I can't say I care that much about Harry having to deal with a kaiju either. For one thing, a Godzilla sized monster would tend to diminish zombie T-Rex Sue as a great supernatural spectacle; plus, I stopped being interested in those kind of supersize monsters a long time ago. So the next couple of books really need to remind me how much fun the series was before Changes.
P.S. Nobody reacted to the point I stated earlier, that one the Knights of the Cross could have taken Karrin's place on the chopping block if Nicodemus did use the Barabbas curse. It was pretty clearly stated by Michael in Death Masks that they had the ability to do so.