Switch needs an enormously strong fiscal Q3 to come anywhere even close to Nintendo's bold forecast. This isn't exactly the best way to start that, particularly since these October numbers include the Smash Ultimate bundle. Being down YoY when last year was hindered by stock shortages for the Switch isn't something that should be made light of.
October was around when the shortage really started ending in North America side of things. The only thing that was truthfully out of stock was the Mario Odyssey Bundle, and the game for that went on sale of that month.