I think its part of the annual replacement program. If a new tower is built then added pressures will blow out old pipes. And yes, those are original pipes so those go back to the 1950-60s.
We always tried to work with VDOT to find out what roads they planned to pave in any given year and get in beforehand. Makes zero sense to have them pave, we come in and tear things up and have to pave it ourselves. Didn't work perfectly all the time but when it did its a beautiful thing.
Enjoy a new water main!!