Commissioner Gordon doesn't appear in the OnStar commercials featuring Batman, but his voice can be heard when the Caped Crusader makes a call to his office from the Batmobile. We can tell it's not the Commissioner Gordon from the 1966 'Batman' series, and since it's not taking place in the Cineverse, it's probably not Gary Oldman providing the voice either.
It's not a recastaway, and I don't think it should be a theory of relateeveety with this new Commissioner Gordon being the son (or even grandson) of the original. Instead, I'm going with it being a totally different man as the Gotham City Police Commissioner. "Gordon" is a fairly common name and after forty plus years, it was pozz'ble, just pozz'ble, for the latest man to helm the department to be named Gordon.