No. I am a supplier to the coal industry. I am in coal pits almost daily. IN Alabama and Eastern KY, and West Virginia, the coal pits are in hilly areas, but not so much in the mountains.
Often times these operations are classified by how they dispose of the overlay. In those mountainous areas close to your location where they are mountain top strip mining, the overlay aka waste aka fill is dumped in ravines or hollows.. It is often called "head of the hollow" dumping. And as you pointed out, these ravines, or hollows, that get filled become level land which can be developed.