Ok, this is in all the Betas that allowed the Charging Sprites to be changed. In the original animation, instead of going to the second frame in the charging animation you have designated, it horizontally flips the first frame and substitues that for the second. Basically, it acts as if Link is walking up, just with the first frame of the Charging Sprites. This is with the Original Animation.
Original Charging Facing Up Bug
Isn't that how the NES walking animation has always worked?
Yes. In fact other "facing up" animations (swimming, walking, etc) use flipping instead of animation when walking up. That's just the behavior of the Original animation style.