Aren't things the opposite of how you describe? My understanding is that the big govt consulting firms exist to allow the govt to access competent developers who are paid market wages since the govt is constrained from paying govt employees adequately. The US digital corp is an attempt to hire good developers as govt employees who would
replace some of the current developers working for the big consulting firms.
Now, whether the strategy of providing a less terrible govt work environment, and a more inspiring story, will actually be successful in outweighing the still-extant salary limits is very unclear. But this is at least an attempt to reduce the reliance on consult developers and the corresponding middle-man fees taken by the consultanting firms.