Just went into practice mode to check it out and I will be damned if the wake up ex shadow kick didnt hit me every time regardless of which way I threw.
You hit the nail on the head versus Cage. Don't bother doing forward throw until it's patched. With the back throw, you can get a free jump in that causes the opponent to whiff a wake up move if they don't do moves that hit about them. (For example, hatchet) Or moves that get them away. (Elbow dash, super man, etc etc) Can't do the same jump on Kano, Kung Lao, or Baraka however.