Not all Coal jobs are coming back. The power plants have already converted to gas.
Newest version of coal plants are not like the old. Can switch between coal syn-gas or natural gas burning operation. Lignite fueled (Allam Cycle) North Dakota plants will deliver 52% efficiency once on-line.
Capital costs projected about $1000 per watt capacity, which leads to a 350 megawatt installation for $350 million —breaking-ground to electrical generation within two years. Compare that costing relative to building a nuclear, or a combined cycle natural gas plant.
A lot of power plants can switch between coal and NG.