Those rumours are going to persist for a while after it emerged that Mattrick at Xbox was in negotiations to acquire Zynga. Then the social network’s market value dived and those negotiations were pulled from the table, but that is why Matrick was brought in to replace Zynga founder, Mark Pincus, as the CEO of Zynga; to right the ship.
And what happens if he can do that? Do the negotiations come back on to the table? One can only assume so.