Reopening a closed mine of any type requires meeting or exceeding safety standards in everything. If there are any that cannot be met it's done.
All grandfather clauses the operation had enjoyed before the closing are gone. The sheer costs of that are enormous.
Then toss in coal is not in demand as before making profit speculation a real thing.
If you dig it who will buy it?
Steel industry is in shambles, power plants also shuttered and need serious updates to reopen. Maybe to convert coal to gas for current operations? They already have a steady supply coming in.
Maybe fearless leader envisions steam powered zepplins providing luxury travel for the rich in a dementia induced fever dream but a reality is those mines closed for safety and not profitable.
Does anyone actually in the coal industry fall for this crap? They still have a few power plants out there using it somewhere, but who would use increased product?