There should not be any movement with the driveshaft installed in the car , no up or down and no side to side movement, EVER It should rotate smoothly in a straight plane, no wobbling Wobbling(up or down or side to side) makes vibrations, straight and true do not
I agree in theory but every driveshaft that I can recall had some slight play at the trans. The splines are not an interference fit, they do slide as they rotate. My Charger has the best collection of parts of the cars that I own and even it has a small degree of slop. Zero drone, zero vibrations other than the engine.
It should rotate smoothly in a straight plane, no wobbling 
