You have the same reclamation costs for any strip mine. Wyoming has sub bituminous, not bituminous. The benefit of Wyomng Powder River Basin subbituinous is low sulfur and nowhere near as much furnace slagging as lignite.
You can deal with slagging — it’s been done successfully for decades. Cyclone burners were a slag-lined high-temperature vortex burner. High temperatures leading to high NOx were problems.
The main reason for the end of lignite mining in Texas was the vast reserves of natural gas that have been found, thus making lignite-fired plants non-competitive. That is why you see long coal trains headed down from Amarillo with “sub-bituminous” coal in them to take the place of the lignite. From what I have heard, many of the plants have switched over to natural gas.