I think tony was never seen as more than expendable. Look how he did Omar with no evidence- Sosa never trusted him from the get go. He was just the pusher in America for him nothing more nothing less. A pawn that could be easily discarded if the need be.Sosa had to feel like he really trusted Tony. Only real way was to catch a body for him.
But Tony already caught bodies for Frank
Tony was in too deep to flip. But he never treated as more than a pawn in his game. The real power was at that meeting.