Not in this case. This is a notification that you are starting to fall, meaning your velocity will be whatever it was before actually falling (in this case, the horizontal walking velocity), and on the next update gravity will be applied and you will actually start moving down. On the other hand, when you jump the Z velocity is set and then you enter falling mode (because the velocity caused you to leave the ground).
I think this should work (once you change the check to Z velocity or not). However I still think it’s worthwhile for us to add a notification when this specific case happens so you don’t have to do this sort of thing. I can think of one case where my suggestion won’t work, which is when you walk off the edge of a moving platform because we impart its velocity to your own right at that instant (so the zero Z check wouldn’t work there).