Gary Wang and Caroline Ellison did make a plea deal so that makes it seem like they are going to fully prosecute SBF. Any deal SBF makes will likely be to keep him from spending the rest of his life in prison.
It has been said elsewhere that he may be able to cooperate with forthcoming indictments of other players, such as CZ. So far though this is just speculation.
What is their to give up? CZ knows how to run an exchange and SBF doesn’t.