The effect would be transient, and very brief because the drag of the canopy is large compared with the momentum of the load. You can observe this by just looking at parachutists (or air-deployed loads) which, within a second or two of being released at high-ish airspeeds are descending with the load hanging vertically beneath the parachute. If there was any significat lag between the wind-speed change and the load's velocity then it would be hanging at an angle from the canopy. But it doesn't .
Also even if it WAS true please reference back to my post above where I point out why the aeroplane would most likely be descending in an attitude in which any lift developed would ne negative rather than positive (with or without a conveyor belt).
PDR