I think it'll do around 22 million, so I voted 22-25 million.
It's gonna be a ridiculous year for software, plus OLED model will start having better stock. I would guess the OLED model would drop to $300 as well, with the original dropping to $250 (and maybe getting discontinued).
Software is Pokemon Legends, Splatoon 3, Kirby, presumably a DK game, presumably a Metroid Prime remake/remaster (1 or trilogy), advance wars, BotW2, new Mario + Rabbids, presumably Bayonetta 3, wouldn't be surprised to see (read: hoping for) a Zelda WW/TP pack, probably some other moderately big games, and I gotta think maybe a new 2D Mario game would hit as well cuz 2023 seems a little late to release a game as big as that. That's a ridiculous year. Multiple 10 million sellers and maybe even two or three 20 million sellers.
That software lineup on top of possibly a little bit of a hardware price drop and I'd be surprised if Switch doesn't get around 22 million. It is certainly passed its peak now and will drop but next year looks insanely strong. So a drop from 24/25 this year to 22 seems reasonable.