All the people weeping into their Haagen-Dazs because the mean old AJC reported this story less than 24 hours after the (on the surface) joyous Byfuglien signing don't seem to have a clear grasp of the situation. The Byfuglien signing and this depressing news item are two sides of the same coin. In other words: they're CONNECTED. Dudley and the Spirit put extra effort/money into signing Byfuglien to make the team more appealing to new investors/buyers, and I wouldn't be shocked if Byfuglien signed because he and his agent knew that the team will soon be in someone else's hands, whether in Atlanta or somewhere else.
The possibility of moving might have made the contract especially appealing. New owners, new market, new fans, new level of fame and success, etc.