Yes, it looks like I was missing the cast. In my code, I didn’t have the line
this.app = (SimpleApplication)app; // cast to a more specific class
My code implements the Application interface, rather than subclassing the SimpleApplication class (I’m trying to be future-compatible, given that I read that the plan was to switch to Application as an interface, since “SimpleApplication especially is a mess”). It seems the documentation has an implicit assumption that users are still using SimpleApplication, hence my confusion.
So I guess that it does work correctly as-is and doesn’t necessarily need to be fixed. It’s just confusing for those using the newer Application interface.l