Crab just beat me to it.
A heavy machine will initially fall faster, making the rotor RPMl go over the upper limit, so the pilot pulls some pitch to control the revs - slowing down the ROD.
At the bottom of the auto, a light machine will have the lever on the floor, before the flare, with ALL the pitch available to cushion on, but a heavy bird will have the lever much higher with less in reserve - making the flare very important to ease the lever down and recover that ability to cushion on. However, he will also use more lever for the cushion, being heavier.