It is possible but to achieve that level of sales you need to push for it.
Switch still has no price cut so it shows they will probably keep the console going for a long time.
We also can see, atleast in japan, that the Switch lite, although less expensive, is really far from being as attractive as the hybrid Switch. So a price cut has the potential to drive a lot of sales. Mainly knowing Nintendo's appeal is quite large and touch families and casual gamers more easily than others.
They could also release a new upgraded model. I feel like the pandemic will keep helping the gaming industry like in past recessions. I do think the Switch will have the advantage tho for being less expensive.
Predictions keep going up every year. We said 100 millions last year and now most expect 120 millions. I'm sure next year it might be more.
Nintendo keeps on surprising us with the Switch and i'm excited for what's coming later. But it will all come down to what the goal is for it. Will they profit of the Switch while it last since they have only one system or will they launch another one quickly by fear they will lose money if the sales go down too much ?
We'll see, atleast they don't have competition in the hybrid/market departement so we shouldn't see another GB/DS scenario. The Switch also doesn't feel as dated as the Wii did in the HD era, which was quickly rejected by the casual crowd.