User blog comment:Savalric/Feeling bad for Urahara/@comment-5147109-20131114180145/@comment-11051098-20131116003808

Good point. Kenpachi told Ichigo that Yamamoto gave Kisuke a "bunch of orders" during the preparations for the war against Aizen and the Arrancar, so he could have repelled the exile at that point, seeing as Kisuke went to SS to see his Kidô spell taking effect when Aizen was sealed.