Yep, Rosberg obviously told how to reset the car and drive the gearbox. If not for that info, Rosberg might have lunched a gearbox and lost all points, or at least lost second place to Verstappen, either due to the fault or whilst trying to fix it himself.
Rosberg should get a penalty, and the rule changed for the next race if they decide to loosen the rule.
Otherwise, it's Hamilton being brilliant in the wet and dry, Rosberg showing he's really, really weak in the wet, and Verstappen showing he's a champion of the future.