I've got no sense for China. I'm still waiting to find out more about how China will receive an actual console. It could be almost nothing, or it could be a huge ton. My biggest skepticism about China has to do with supply though. Nintendo is about to have trouble supplying the places where it is well established. I am not sure how they can supply China at the same time. It might just make Nintendo even more short supplied.
In the end, I still think Switch total sales will surpass PS2 even before China is taken into account. After adding in China who knows? It might be a drop in the bucket or it might double their total sales. I need to see how Nintendo is received there before I can decide.
I can't imagine the Switch beating the PS2 with no new 3rd party games from 2021 ported anymore. The Switch would need to sell well until 2026 to reach 150M.
You should have given a vote anyway...The middle of the Gaussian curve obtained with many votes should give a realistic estimation.
The number of third party games on the Switch is accelerating and will continue to accelerate. Most Japanese games from here on are going to be on the Switch. Western games? Who knows. But Japan is so heavily for the Switch that 90%+ of its third party games are going to get a Switch version (exclusive or multiplat). This is going to keep Switch going strong enough to pass the PS2.