Otto, you are absolutely right about shorter tires and more rpm required for the same speed. The Good news however is unless you change the speedometer gear to compensate for the shorter tires, the speedometer will still show the same speed as before at a given rpm. It'll be wrong of course, but the driver may well be none the wiser unless he checks travel time between mile markers or has a GPS speedometer app on his phone. Ignorance is blessed (perhaps).
RonR
