In 1 year you will see xD
Without any 3rd party support it won`t will sell nicely over a long time, In germany (Duesseldorf, Cologne etc. there are no stock issues you can buy it everywhere without any problems, see the reality its a slightly better selling Wiiu. And yeah it sold 4 million but why'? Wiiu only gamers has to switch their systems because they dont get any more games.
Xbox will be the most powerful system by november 2017 alot of technic freaks will get it only to see their games in 4k, so as we all know it will sell nicely in the the end of the year.
but the bigger problem the switch has is the ps4 because this is the casual mainstream console this generation and everybody buys it if he`s a gamer or not so nintendo can`t hope for the casual wii effect.
That's at best a niche market, most Tech Freaks own a high end PC, and it plays all the same games as X1 minus maybe Halo. X1 has no clear path going forward, it relies too much on games that are available on other platforms. I do honestly believe lifetime X1X sales will be less than Wii U.
Lastly, you can't compare this to the Wii U. It's significantly over Wii U sales in less than half the time. It took Wii U 9 months to sell just shy of 3 million units, and it took Switch a little over 3 months to sell more than a million of that. You also can't compare the Switch to the PS4. PS4 to the public is seen as a traditional console, while the Switch is seen as a device where you can play similar PS4 quality games anywhere you go. They each have their own market, and they will both continue to be sucessful.