Nintendo have made the formal announcement that the Switch 2 will be available this year.
Just watched the teaser trailer and it looks like a slightly bigger Switch. There’s probably more to it, but detail
is scant and rumours abound.
It does say that it’s backwards compatible with Switch games (both digital and physical) but that maybe not ALL Switch (1) games will be supported. It also says there will be Switch 2 exclusive games.
https://www.nintendo.com/successor/en-gb/index.html