I am not convinced the lighting by dynamo issue makes a lot of sense where an e- bike carries, in a relative sense to the power required for lighting, a "gert great" electrical energy storage battery?
I know the Germans, so probably elsewhere on the continent were saddled with a legacy issue carried over from conventional bikes of having dynamos, so electric power did not rely on the health of a few pen cell batteries. However, given with the e-bike's whole purpose needing a huge and viable battery, seems to me time to revisit any concerns the battery for lighting might be dead.