GM has a whole bunch of new electric vehicles on the way. Most will use an all-new battery and powertrain system that GM is working on now. But there are two known to be coming fairly soon that that will share the current powertrain technology used in the Bolt. (They’re thought to be a small Buick SUV and a Cadillac of some kind, but GM hasn’t shared details yet.)
Those new vehicles may be very different from the Bolt, but they’ll share quite a few parts under the skin and will be assembled in similar ways. It would make sense to make them at the same factory that makes the Bolt.
I think GM is discontinuing the Sonic so that it can reconfigure the Orion factory for mass-production of electric vehicles. Suddenly its plan looks a lot different, doesn’t it?