According to that article, they disagree with this idea as applied to an industry (coal) that has long been a key part of West Virginia's cultural and political identity.

Also according to that article, former coal miners are more open to retraining where other industries have jobs readily available and/or where coal has no credible chance of comeback in that area.

None of that contradicts my suggestion as applied to the health insurance industry, which isn't really part of any cultural identity, and which would clearly not be about to rebound quickly in a single-payer world.

Retraining could even be pretty quick if they retrained to other forms of insurance, especially life insurance (which still cares about individual health) but there are many other kinds too.

What makes you think the other insurance markets can absorb anywhere near that number of workers, without collapsing wages and causing even more misery?

I don't, but they can be among a menu of several destinations for them. Certainly not the only destinations.