I always thought Michael said those things to keep control of Tom and keep him "in line." It was to remind Tom that if he betrayed Michael, it would be found out and Tom would be in big trouble. just my 2 cents for what its worth! Kind of like when Mike "pretended" to be mad at Pentangelli right after the "hit" on Michaels home. It was to control Pentangelli into getting him to do what Michael wanted.

Anyway, if Tom had said, "yes I'm moving to Vegas" (which he never would have because he was loyal to Michael) then Tom would have been put out for sure.