You can still have RN dev focused on Apple nuances, and another for Android? They can work together towards a common goal, what you're also missing with React Native is that the UI is platform specific, the business logic is fully shared however.
My experience is that anyone who is sufficiently specialized in either platform will select to develop natively for that platform over using RN, since RN imposes lowest common denominator UX for both platforms, more or less.
