just when were the dancers chosen for TII im confused

[MJfan4life]

ok so i read this just now You are not allowed to view links. Register or Login and in it it says MJs dancer Shannon turned down a gig for britneys circus tour cuz if conflicted with This is It. well i find that weird cuz britney started rehearsing back in january of 09 with her first show on march 3, 2009. the world didnt know about TII until march 5th and rehearsals for TII were supposed to be held in april. so how did he know about TII back in 08 while he was working with britney back in september of 08 during the time she was filming her womanizer video and getting things started for her tour unless he was already chosen by MJ and fully aware of what was to come.

[UTisNUM1]

Sometimes performers do a second leg of a tour where some of the crew/dancers/backup singers can't go overseas due to personal reasons, maybe he was doing TII and then was called back for the Britney Tour and told Britney he couldn't.