I wouldn't be surprised if he was lurking about in the shadows during the battle, still having Ivy's back. She knows it as well, but won't acknowledge him for a number of reasons, many are the same as the reasons she didn't acknowledge Harry. Not just to punish both of them a bit for what they pulled at the end of Changes, but she now needs more than ever to send a message to the rest of the supernatural world that she is independent and a force to be reckoned with, as her grandmother was. The Archive keeps score, calls balls and strikes, it has no friends.