Currently Online 
if they take a long time to launch a successor (Q4 2025 or beyond), 160 million is quite likely to happen.
If they launch a successor between Q1 2024 - Q1 2025 (so in a 5 quarter range) which is super likely, 160 million is tough.
DS was the best-selling Nintendo platform of all-time, and sold under 10 million units after the 3DS launched in Japan (and shortly after in the rest of the world). Keep in mind that the 3DS screwed up its pricing, lack of an eShop right at launch, and some early software misfires, and the DS still didn't capitalize on that in a massive way.
While the Switch and its successor will not be identical to the DS to 3DS transition, it's unlikely that the Switch sales are above 10 million more units after its successor launches.
Lifetime Sales Predictions
Switch: 161 million (was 73 million, then 96 million, then 113 million, then 125 million, then 144 million, then 151 million, then 156 million)
PS5: 115 million (was 105 million) Xbox Series S/X: 48 million (was 60 million, then 67 million, then 57 million)
PS4: 120 mil (was 100 then 130 million, then 122 million) Xbox One: 51 mil (was 50 then 55 mil)
3DS: 75.5 mil (was 73, then 77 million)
"Let go your earthly tether, enter the void, empty and become wind." - Guru Laghima
