Animal Crossing will move units. What will be the big release(s) in holiday 2020? That is tough to answer. I'd love to see Mario Odyssey 2 or a full blown Mario 64 remake. BotW2 is probably a bit further off. I wonder if a New Super Mario Bros. Switch makes sense or if Mario Maker 2 has satisfied the desire for 2D Mario games. A Pokemon remake would sell plenty as the series always has done.
Nintendo likes making profits over its console sales, so a price cut next year only makes sense is if they can still profit. I'd see the Lite dropping to $180 and standard Switch dropping to $249, but not lower. More likely Nintendo does a bundle with MK8D than drops the price.
With both NSMB Deluxe & Mario Maker 2 both releasing this year, I have a hard time seeing a new 2D Mario releasing next year.
Odyssey 2 would be great but it has the same issue as BotW2 or Pokemon in that they will sell a ton of software and will move a good amount of hardware but their strength will be dimished by the fact that they all already have installments on Switch.
And I agree that we probably wont see a flat out price cut next year, added value bundles are more likely.
Overall I expect sales to slow down next year, not a huge decline though, maybe something like down 10-15% YoY so still very high sales.
When the herd loses its way, the shepard must kill the bull that leads them astray.