If SC only for the 850 in 2020, Poo would be focused on profit per unit, and not unit sales. Same for AC if they only offer the Alpha 800 at SC.
While this is likely better in the short-term for dealers, and for resale of 840's by owners, they are abandoning the sales unit lead to Doo, mountain or trail. By offering the Summit 850 both at SC (X and SP), and in season in the SP, Doo dealers avg profit per sled might be lower, but Poo will never sell more mountain units than Doo. My guess is - they'll look right past the dealers and resale for existing customers, and sell the 840 in season in 2020. They kinda know how volume and market leadership works. Dealers will have to suck it up. Customers always have to suck it up.