It is a confusing notice. I did Windtower a few months back, and read the sign as meaning that the area of West Wind Pass was also part of the closure. Perhaps I should have read it more thoroughly! I cut around below the pass to ascend Windtower, to miss the area of the pass. To access Rimwall, you cut off from the West Wind Pass Trail even lower than for Windtower, so you don't get close to West Wind Pass, anyway.