Let look at Tesla. Why when they are still in stage of perfect-ing (completing) electric car, and began to built electric truck? To me, the reason is simple: they have not find a real method to store energy in battery, they will use the larger surface of truck to place solar panel. This method is nothing new, and the efficiency is too low.
I agree with 67Dart273. Both Elon and UPS are not healthy economy. The contract could be their move (marketing) in hope getting back to where they hope it to be.