Given the fact that there really isn't any where else to build products, where would have they? The demand for ICE powered trucks isn't going away till it gets forced to. BOC is a transitional point and most likely an older plant would be closed once that transition happened.
Maybe they'll do dedicated charging area instead? It would be fairly easy to implement a reservation system with fines if you don't move your car by the time you signed up for.
The bigger issue is how to figure out the density and then maybe have a future reserve area if say 80% of people who live there have EVs