It is possible to reverse the scale of the objects, but the offset between them is not taken into account. I don’t think you’re looking for result like on the image below.
The reversed array is not animatable and is not made directly within Array modifier. I used a single face object (plane) for making the array then scaled the object along Z axis which changes the height of the polygons and their surface arrea. After applying the modifier I used DupliFaces with the desired object and Scale option turned on.