Yes, I saw that issue but half of the discussion seems to be about changing the behavior of Py_Initialize() permanently so that double-initialization is no longer allowed. If pvpython is double-initializing then it seems like we should not.
I’ve looked in VTK/Utilities/PythonInterpreter/vtkPythonInterpreter.cxx and it looks like we’re trying not to double-initialize, but in the debugger, _Py_InitializeCore is called twice, once from vtkPythonInterpreter::Initialize (when it calls Py_InitializeEx) and once from vtkPythonInterpreter::PyMain (when it calls Py_Main).
This pattern of calling Py_Initialize and then Py_Main appears mildly frowned-upon and the original issue above also links to these: