As Adjt said, it'll depend on whether the USAF consider that the capability is worth the hassle.
Given the possible numbers it'd be a license-build in the States, but that's par for the course anyway.
They'll probably arrange loads of demos and technical meetings etc but the chances are USAF will stick with what it's got for the time being. C27, C130, C17 & C5 is a good spread of capabilities.
Yes, there's a gap between C130 and C17, but does it really need filling?
It's certainly still worth Airbus taking a punt on this - 200+ airframes would be more than they've sold to everyone else combined!