Well like earliest possible when next gen Nintendo console can arrive is 2022. more realistic 2023-2024. so this talk is way premature, I mean we still dont know what current Switch will bring us with revisions.

But, I am certain that Nintendo will continue with Switch, so most likely we will have Switch 2, they will definitely have some new gimmick also (very possible AR/VR support) and they will keep to Nvidia + ARM. Also its way to premature to talk how powerful could be because in around 5 years we dont know what kind of mobile chips we will have (much stronger than current ones in any case).