If the Switch is on 150-151 right now, it would be selling far more than early 2024 to reach 155 by March, and we already know it's been selling much slower, so I doubt your prediction is currently going to be accurate.

150 million+ for december 31 is as good as guaranteed.

Waaait, waaait... 170 Million PS2 sold! I mean... 190. Sony does a commemorate plaque to "demostrate it". FInal number... 490 Millions sold.

It is difficult for Switch to get 160 million sold without a single nice cut in price in 8 years.
Also, Nintendo did not say anything about what will happen with Switch production after Switch 2 in the market. If Switch 2 gets a massive demand, Nintendo could not make any other machine than Switch 2, even if they pretend to do it.