Actually, it makes more sense now. Remember this is not about logic or sentiments, but politics. All the board needs to do is create dissatisfaction about Messi, check. Unsettle the player, check. All they have left is to create a plan to reinvest the money, Reus, Koke, new stadium, and then convince a good amount of board members that this is the right thing to do for the club, that the club is bigger than just one player, and it could happen.
All you who are thinking this could never happen are being a little naive. Granted it is a long shot, but these fuckers leading the club are politicians and businessmen, and crooked to boot. They don't necessarily think with passion and logic, but with power and politics.