I haven't heard one single thing about him causing any locker room issues. In fact the only thing I read was that Noah was so excited about him returning that he wants to get an apartment with him.
I'm hoping he doesn't cause any in the future. That worry is based on his occasionally recurring 'no hustle' episodes and his odd & somewhat alarmingly nomadic career.
I love the roster so I don't want chemistry issues to mar a championship run. Cespedes is clearly a fearsome hitter (though his OBP is poor).