Nah, I'm pretty sure she won't pull outta the Open. I'm pretty sure that she won't win it either, though. She has the game, but not only is her toe hurting, it's prevented her from getting into serious Slam shape that she needs to be in in order to win it. Just like with Venus - her injury is fine. She's just not in any match shape to play a Slam.
Expect JHH or JenCap to come away with the honors. Kimmie has the game, but I don't think she has the "head" to combat the pressures of this New York crowd who demands the best outta their players - no exceptions. JHH & JENCAP are both cantankerous enough to handle the crowd.