When you think about it, everyone who ownes a switch is a potential switch 2 buyer, imagine theres a new 3d mario, a new mario kart and metroid prime 4, maybe some 4k patches for golden games at launch available and you see an epic trailer of the new console in your cinema, where they told everyone you can play your old switch games with better graphics, games from a time where some people where young or met their wive, or they started building a family, played with their kids etc. For me at least, this would shake the fabric of the universe and set an instant hype, i met my wife 2017 and we both loved nintendo
Just wanted to point out, if nintendo does the launch well and deliver games steadily, which i think they will, the hogwarts studio purchase is a good indicator, switch 2 sucess would be definitly possible.
(Sry for bad english btw, this is not my native language)