First things first : air pressure is lower on the upper side, and there is some downward movement of air behind the wing, these things are 100% certain.
However, the newton explanation seems wrong, you'll see why later in my post.
I think the problem is even more confusing if you consider the other side of the relative movement.
I mean, in order to explain lift, most explanations consider a wind tunnel, with the wing stationary.
However, if you consider a real airplane, then the airplane is moving and the air is stationary.
So the only way this air above the wing could be accelerated is if it moved
backwards. Which is really a mind
Really, I've completed a master's degree in aerospace engineering and we never learned how to explain lift in layman's words.
We only learned that lift comes from a circular movement of air (which you already know about) : air moves backward above, forward under, upward in front of and downward behind the wing.
But the reason why this circular movement would appear is just because the fluid mechanics equation make us come to that conclusion.
Obviously I forgot about the involved integro-differential equations almost as soon as I saw them
