The thing is sounding rockets do exactly that and are still in service (vs somehow unfucking an ancient plane that hasn't been serviced in decades with tooling that no longer exists) and there are multiple companies out there operating supersonic drones for high speed tests of whatever you wanna do.
I dont see the value in bringing the blackbird back into service. I think its more likely that they want to freshen up the paint and park it at some press conference / event.