From what I could see, there was zero improvement on the new part. Given the mounting design, there isn't much of a way of increasing the durability of the part as far as making it thicker. I'm sure they could change the material, but that costs pennies in overhead and we can't have that, now can we?
*EDIT* There was a TSB issued for the '15-'16 trucks, but in the TSB it shows two different style blend doors. The first has a square drive, the type I replaced had the "star" drive which is supposed to be the better design.