I googled our house and noticed our neighbor's pool wasn't on the image. They built that in July/August, so the image, if it is the new facility, could be a few months old. The large amount of hiring could be the staffing of the new facility. Just my thoughts.
About the few cars in the parking lots. My guess is that to run this facility you only need a few higher paid managers and engineers. The majority of the production and office workers are probably lower skill lower paid. Also, I believe that that is a regional bus terminal right across the street.