Exactly. In order to be used in Python, QVTKOpenGLNativeWidget would have to be wrapped with PyQt/sip and PySide/shiboken. In other words, wrapping this class is very different from wrapping other VTK classes, and it would require a lot of work.
That’s why people use QVTKRenderWindowInteractor.py instead. It is a pure Python class that doesn’t require QVTKOpenGLNativeWidget. Please see the example.