>>Did this even happen? I cannot find any articles in which miners were told to learn to code.

Then I guess you really didn't look to hard:

https://thehill.com/changing-america/enrichment/education/47...

snip:

"During a rally yesterday, Democratic presidential candidate Joe Biden spoke to a crowd in Derry, N.H., a town that many miners call home. He acknowledged the economic setbacks and job insecurity that coal miners face these days, and gave them some advice: learn to code."