The story I read says it's among 6 sedans being considered for discontinuation. Even if they axe the Volt, it will be produced through 2022. The reasoning is that sedans are not popular now that gasoline is so cheap. Consumers are rushing to buy crossovers, SUVs, and trucks.
By the time they made the switch in production, which takes 4 years, gasoline prices will have likely shot back up. Seems the auto industry is always half a decade behind.
If Chevy cuts the Volt, I bet they would replace it with a similar crossover.
Here's the article.