User blog comment:Xilinoc/Ch. 566 (not out yet, but dis gon b gud)/@comment-4794735-20140201215800/@comment-26420452-20140202075727

The way it's been depicted until now, the Soul King's Palace isn't really a separate dimension from Soul Society. In order to go there, you simply get rocketed up and to come back, you take the stairs (or skydive, if in a hurry). Thinking of it, the stairway would be noticeable throughout the Seireitei: does that mean it hasn't finished falling down?

And Mohrpheus mentioned Renji because he didn't hesitate to use Bankai while fighting Mask - an implication that he'd received the Shin'eiyaku.