Just remember, whenever republicans talk up coal, it's about the remaining 6 or 8 old-ass men across the country that still own all of the coal mines. It's not about the people that work for them, or the mines themselves, it's about making sure those 8 assholes are able to retain as much of the wealth extracted from those mines as possible, all while the inevitable end of coal occurs as the market has fundamentally rejected it.
This is why nothing has ever improved for actual miners. The GOP protects the financial interests of the handful, because there is nothing they prefer more than exploiting the endemic misery of the population created by the extraction of their own personal wealth. There really isn't any greater traditionally blue collar, often poor white community to exploit like coal miners, and this kind of misery is what the GOP needs to sustain itself. They simply can't operate without fear and misery, and this group is forever tied to the populist nonsense that the GOP prefers.