If they plan to keep the Switch around as a budget option post-successor kinda like they did for 3DS, then they may kill off the OLED and base model in short order as it wouldn't make much sense to have a $350 OLED selling alongside a $400 or $450 Switch 2.
The Lite could be kept around, but it's also possible they release a new budget model that can "Switch" sort of like the New 2DS XL that released right at the end of the 3DS's lifespan.
It's also entirely possible they just quicky axe the current Switch altogether once the successor hits, similar to the DS and PS4. This is the only scenario in which I see Switch falling short of 160m.