Remember that all aspects of muzzleloading, from the one man business that provides hickory ramrods blanks, all the way to the largest companies like CVA, Pedersoli, and others; only comprise less than 1/1000 of 1% of the total outdoors/sporting goods/hunting/fishing/shooting/firearms/bow hunting/backpacking/camping/RV'ing/etc. market.
We're small potatoes. Which means that the chances of black powder being legislated out of existence are quite good. After all, in the minds of the general public, black powder is an explosive, only good for fireworks, and pipe bombs.
If the Goex black powder plant closes, and fails to re-open, then it would only take a stroke of a pen for Congress to forbid the importation of foreign sources of black powder. Then, only the substitutes would be available, and you can bet that the cost of those subs will skyrocket.