User blog comment:Xilinoc/Ch. 585 - The Headless Star 4/@comment-24153155-20140618145221/@comment-24754636-20140619100229

Then again, we've been shown thus far that they need Kukaku Shiba to go from the Soul Society to the Royal Palace. Why warn about the barriers being left open if they didn't know Yhwach could get up to them?