User blog comment:Xilinoc/Ch. 546 - THE LAST 9DAYS/@comment-1351982-20130717110017/@comment-4207271-20130717151854

Shunsui likely knows about Isshin, due to Fake Karakura and the fact that Oetsu knew means the Gotei likely knows. Plus, since Kukaku knows too, then why wouldn't the Captain-Commander. And if Fake Karakura took soooooo long for one short battle, then 9 Days will take nearly forever. And if not, Kubo could just have it plot-kai'd away, either it being stopped, or... ummm... "re-translated", so he might mean that only Soul Society would be his, so the Shinigami might move to Hueco  Muendo, and bam! Plot-kai'd!