We do not know enough about Switch 2 to say how much it sells. Fact is, the Switch 2 unveil video surpassed PS5's unveil! Thats a good start, reactions are overwhelmingly positive (maybe even the most positive rractions ever for a system unveil- at least its hype level surpasses the ones of every  system from any company ever) but thats only half of the Story! In the US the Dreamcast had a record breaking launch, the WiiU sold 3,5 million in its first 3 weeks (december 2012), the Vita sold 1,1 million in its firt few days WW, but we know how these systems ended... I say a flop is basically excluded but i wouldn't throw numbers like 150 million+ around. What we can say is that the Switch will end with 157 million+ minimum by march 2027 thats as good as guaranteed!

Tbh I'd predict at least 100m because the fact of the matter is the is practically a monopoly on the portable market those platforms didn't have the same safety net as remember 3DS had a tough start and clawed its way to 75m and mind you any poor start Switch has will be addressed even more sharply as it's now their sole platform, the core home console Nintendo fans plus anyone who outside of that demographic can top up the sales to hit 100m.

We don't know how much it will sell sure but we know enough to assess the situations as I mentioned above the hybrid format by default puts it in two parallel markets, the format is also a proven appealing concept which they've decide to not fix what isn't broken and instead build on a strong foundation this leaves the main challenge being appealing to both the Red and Blue ocean consumers again.

Yes, in the handheld marked the Switch is basically the Game Boy right now (GB 118,69 million vs GG ~8 million- lets just add the 1 million Nomand users and the competution did not even reach 10%.). Adding the fact, that the whole PC "Handheld" competition was not even able to outsell the Sega Game Gear's total LTD (~8 million) in its first 2 years+ Switch can be called a monopoly in this segment, but as it is still connectable to the TV it also competes directly with PS5 and Xbox Series (wich it has already eclipsed). Their only direct competition soon will be the PS5 only as long as Sony produced physical games. I am impressed that market regulatores are not the same to Nintendo because of their monopoly as they where with MS before their Activision purchase fearing they could become too strong. Nintendo is clearly stronger in the console space than MS!

It will certainly not be a flop, and will outsell the wii U. Unless they completely lose their minds or the console is unplayable.
As for how much, saleswise. Well it looks like mario kart 9 will be one of the first games being sold. The problem with Mario Kart is that it's not really a system seller but just a game that consistently sells throughout the consoles life. I think when they do the direct in April then we can determine how much it will sell.
I would say between 75-100, based on what we know right now.
The switch sold so much because of the covid boost. That, hopefully please God, won't happen again. Animal crossing came out at the PERFECT time and boosted the switch into the stratosphere. The goodwill of that will make the console sell incredibly well but 150+ probably won't happen again.
This is a good thing, since xbox is rumored to release a new handheld console and there is the steam deck. Rn they are more expensive and niche, but maybe this will get nintendo to get off their high horse and have to brace themselves for competition.

MS is a different situation to portables though as MS was buying up elements that make markets competitive where as with portables Nintendo just blow the competition out the water much like Coca Cola does the is no case for any regulator as it would be like taking prime Mike Tyson to court for winning his fights.

It competing with PS5 doesn't really bypass the point because if someone wants a portable they still buy a Switch, or Switch 2 in future, this basically gets Nintendo's platform in peoples homes and unlike PS5 multiple Switch units can be in one house far more frequently as a result. You're correct that for Nintendo whether someone buys it in the context of a portable or home console doesn't matter as each sale is a sale in both markets although home console wise the PS brand is pretty much undisputed in the traditional approach and in all cases where it has had a strong competitor go blow for blow it took an unorthodox approach (DS, Wii, Switch) and the reality is that Switch is both a great console and portable up there with GB, PS2 and SNES but if Switch 2 was just a home console we'd all be somewhat more conservative with our predictions.

Make your final early predictions before the direct!

My predictions are that the system will cost 399$ and will launch no later than June 2025.

Nintendo needs a $399.99 price tag unless Switch 2 comes with a lot more included storage than we're expecting (say 256 GB or above).

Switch 2 will succeed at a $449.99 price tag, but it's a much harder sell. And $499.99? I don't think we're looking at the struggles of the early PS3 years, but it nevertheless would harm Switch 2 immensely. 

Unless Nintendo drops the ball with price or software, the first full year of Switch 2 (from when it launches to a year later) is looking to be one of the best first years of hardware units in history. 

I agree $399 would help it fly off the shelves, but I'm not convinced Nintendo would price it that low. I'm hoping for a $399 basic model and a $449 OLED/deluxe.

Here's the final pre-direct tally. After the direct, I'll create a new poll based on smaller increments between the 75-150 million range.