Kind of weird that all of a sudden there's no neo-natal surgeon. Last week they had to operate on a premmie baby and Arizona did it....which brings the question, why did they need Addison in the first place? And where was Arizona while Addison was there and she was operating on all these infants?
Good to know someone else was wondering the same thing. What's the difference between a pediatric surgeon that can operate on newborns and "the world's most foremost neo-natal surgeon?"

I have a feeling this might be Grey's twisting reality again. My guess is that hospitals have neo-natal surgeons who operate specifically on preemies and other babies that are different from general pediatric surgeons like Arizona but instead of hiring a new neo-natal surgeon they're just hoping the audience won't notice that Arizona is now doing Addison's job since babies are kids too and they know she's a peds surgeon.