Correct. Every React Native component actually renders into a native view, so on iOS if you use a View (RN) it maps to a UIView when React Native actually builds the UI.
Mapping to UIView is about the only thing that is “native” about React Native. My comment was about Native Script, which uses actual native widgets and concepts, such as controllers, animations systems, navigation, etc.
On the other hand, NativeScript's UI mapping is directly on top of the platform widgets, as far as I remember.