hello_moveit is great for getting something running, but it seems like some users take it as a starting point for doing actual development. Of course, nothing besides very basic planning is even supported. Most features in MoveIt will simply not work since proper launch parameters are required for full MGI functionality.
Here is an example issue that highlights the problem moveit/moveit2#1843.
We should warn about the limitations in the tutorial and directly point users at the MGI tutorial or others for further development.