Lyman,
Lift is equal to the net rate of change in momentum of the air in the downwards direction as it flows by the wing.
On entering ground effect, `upwash' may increase in some places, presumably ahead of the wing, but `downwash' has to increase BY MORE in others, or else there would not be an increase in lift.
Newton deals with changes in momentum, Bernouilli with changes in energy. They are not redundant. Both must be satisfied.