As for the topic... Ignoring that it could be the 3ds successor, It should do 20m, it's just 6m more than what wii u did in only four years... Come on people!
Even wiii u could have done that if it didn't had that short life and got a price drop...
This time I think that Nintendo has provided for the future to be able to reduce as much as possible switch price, so it could reach the 199$ price point in three-five years... A sweet spot, many people skipped wii u owing to its price, many of them were wanting one at 199$ but it never got there or to be precise, never had a price cut, since Nintendo would bleed money due to the costly tablet controller...
Wii u was never popular, so I wouldn't be surprised if its components were more expensive than they were earlier in its life!
That must be why Nintendo hastened its successor, low sales but also low profits ( and losses in the first few years ), is a damaging combination, and Nintendo cares for profits. If wii u was sufficiently profitable, switch would come fairly later! What to expect when your undesired or badly executed controller adds 80$ to the manufacturing cost and 110$ to its commercial price?