Yes, let's not confuse "ground-effect" and "ground-cushion."
I think a lot of helo pilots assume that an autorotating rotor produces no lift. But it should be clear that the rotor must be producing some lift or, as DeltaFree pointed out, the heliocopter would plummet to earth in freefall.
IF a rotor in auto produced no lift, how would we account for being able to arrest both our rate of descent and forward speed in the (ahem, Nicky?) flare with the pitch stick still firmly on the bottom stop?
Even at flat pitch, a rotor moving forward through the air still has the properties of an airfoil. Increase its angle of attack and you increase the amount of lift produced. Therefore, airplane-like ground-effect will apply, but only very close to the ground (probably less than the upper limit we usually associate with g/e in powered hovering flight).
As NL notates, the conditions are changing too rapidly in the flare/pitch-pull to quantify any "benefit" from ground-effect. At the bottom of a fairly steep auto, ground effect will be minimal, and not felt until the pitch-pull.
But come in fast and round-out low. Like an airplane, the helicopter would take advantage of the same type of ground-effect. Unlike an airplane which touches down at a fairly high lift-producing speed, the helicopter will quickly lose ground-effect as the speed bleeds back to zero. THEN, as we level and pull, ground-cushion comes into play.