Considering the polls are saying 85% is looking to buy a ps5, I think Sony will get close to ps2 numbers.
Switch will obviously do great, but you can't really put Switch in the same market segment as ps5/ Series X.
Polls arn't always accurate.
However I do believe PS5 might actually have slightly higher % of market share than the PS4 did.
Alot of people got burnt on the XB1, and may have regretted going that route this gen, and then swap next gen.
Not sure the split will be as drastic as 85% PS5 vs 15% XSX.