I don't know why they'd need OpenAI though. Our government's three letter agencies must have a one hell of a data set to train their own AI on.
The government is just structurally incapable of attracting this type of top A+ talent at scale. They get and keep smart people but not the smartest people. For this, they absolutely need to use industry relations.
Just picture yourself in a position to work at either OpenAI, or GE, the DoD or GM. The average tech worker will much prefer the hip SV company than the old quasi-government dinosaur corporation or the government's agency.
The number 2 reason is the pay is shit.