We have definitely not stopped using React Native! Not sure where you got that impression. We continue to heavily invest in it as well as native platforms and make a case by case decision for all new products.
Also interested in hearing if they really stopped using React Native as a whole. Especially since their react-native-maps library is the defacto library for maps. It would be quite scary if they decided to stop using React Native.
Right now, the only thing I'm currently aware of is that their navigation library (native-navigation [1]) is pretty much unmaintained and they are trying to plan out a transition to move it under react-community.[2] The only thing that hints at their slowing use of React Navigation is the mention of conversion to React Native's navigation getting a much lower priority to the point that the native-navigation library has essentially become unmaintained.[3] But when I initially read that, it didn't come off as Airbnb deciding to stop using React Native.