A listing at Julien's Music Icons auction showed a letter that Barry Siegel - former accountant of Michael & an executor of the 2002 will - was also rehired before Michael's death just as Frank Dileo and John Branca rehiring.
An article by LA Times had mentioned the firing of Cannon & Co. in a May 2009 article
http://latimesblogs.latimes.com/music_blog/2009/05/deep-pockets-behind-michael-jackson.html
In April, Jackson fired the accounting firm, Cannon & Co., that had worked for him for a year, according to an accountant who worked on his finances. Jeff Cannon of Cannon & Co. said he received a phone call from an assistant of Jackson who said the singer no longer required his services.
The letter that's being auctioned by Julien's now shows that Cannon & Co was replaced with Barry Siegel.
https://www.julienslive.com/view-auctions/catalog/id/72/lot/28890/
This might show that Michael was in the process of hiring his old staff back.
An article by LA Times had mentioned the firing of Cannon & Co. in a May 2009 article
http://latimesblogs.latimes.com/music_blog/2009/05/deep-pockets-behind-michael-jackson.html
In April, Jackson fired the accounting firm, Cannon & Co., that had worked for him for a year, according to an accountant who worked on his finances. Jeff Cannon of Cannon & Co. said he received a phone call from an assistant of Jackson who said the singer no longer required his services.
The letter that's being auctioned by Julien's now shows that Cannon & Co was replaced with Barry Siegel.
https://www.julienslive.com/view-auctions/catalog/id/72/lot/28890/

This might show that Michael was in the process of hiring his old staff back.