Ground effect and auto.
Ground effect exists at all heights it just becomes negligible very quickly as you climb. Logically all wing borne ac fly by exerting a downward force on the air around them, this is balanced by a pressure in turn being exerted on the ground below, so the proximity of the ground below will have an effect on your "wings".
During a flare at the bottom of the auto there is not a steady state of pressure and your deceleration is brought about by accelerating air downward. At first the ground is unaware of this but it doesn't take long to realise and exert a presure to resist the downward movement of air which in turn pushes you back. So I guess I am saying there will be ground effect but not as noticeable as in a stable state constant low level flight/hover. To be honest as previously mentioned, amongst all the other effects it will be barely noticeable.