I am willing to wager he is not there to clean up the Kingdom Hall or bring any meaningful changes to your Kingdom Hall unless there is a "splinter cell of Apostates".
Gossip and conspiracy theories abound when a high ranking player like my big brother moves into a Kingdom Hall. They can be used to help with the books or motivate the Congregation but often, in my experience (I am sure other elders who served over thirty five years here can agree) they moved there for no "clean up" or "shake up" only to live!
There is only one congregation I was in that blew up (Avila Beach) and I left that Kingdom Hall when I saw the writing on the walls years before it was disolved and people were sent to San Luis Obispo, Grover Beach, Ocean View. When the CO told me "If you don't like what's going move!" that was my que to leave the snake infested Avila Congregation.
In my experience we have had people move out from Bethel to live in our area because they love the weather after giving a talk. Special Pioneer-Elders, Circuit and District Overseers move into the area and it still does not mean "evil is lurking and a witch hunt is about to erupt".
The average publisher rarely sees all the hell busting loose behind the scences, please don't worry about this because it sucks to get your hopes up high! love and joy be with you!