I was reading Pep Confidential and it says very clearly that the Barca board were trying to sell him since 2011.
"The club will then buy Thiago, whom Barcelona have been trying to transfer since the summer of 2011, a year before Guardiola left the Catalan club."
"The player has already reached an agreement with the Munich team and is not interested in going anywhere else. No one from Bayern anticipates any opposition from Barca, who have for some time been very open about their wish to sell the player. When Guardiola was still coaching Barca, in the summer of 2011, the club was already testing the market. Later they agreed to include an escape clause in the players contract, which detailed that if Thiago played less than a stated minimum number of minutes per year, his recission fee would drop hugely, to €18 million instead of the phohibitive €90 million figure in the original contract. Later having won the Spanish league, nobody at Barca was interested in changing the team dynamic just so that Thiago could reach the target amount of playing time and it seems unlikely that the club is going to reject a reasonable offer now."
Maybe consider that before calling him a traitor...