Well, it depends on the penalty clauses.
The cost of the FSS network is a barrier to entry for a competitor, so it would be much, much harder for the Guvmint to take it back and rebid.
My greatest fear on an outsourced ATC (aside from prohibitive user fees and a group of airlines that keeps GA "out") is that the barrier of rebuilding the system becomes so high that it will be nigh on impossible for the contract to be rebid. Once that kind of contract is let, the winner is virtually guaranteed a lifetime contract. The Feds will find it too expensive to take back, and competitors won't be willing to put up the $$billions in costs to develop the systems. That ensures that substandard performance will meet with minimal penalty. Simple economics.