I've been watching inventories closely since last August when I visited 4 local gun stores and was unable to buy SPP. It is my opinion that supplies will NOT increase anytime soon; the shortage is real and people are now hording the few inventories that remain.
Powder Valley - a high volume low cost retailer is a great example. They are out of almost everything in primers and powders. Another example is auctions for primers on Gunbroker.com and GunsAmerica.com. Sellers there are listing primers at prices that significantly exceed the fair values and they are getting multiple bids.
All this started before the November election but it has accelerated since then.