Nintendo has no competitor on portable side. Gb/a era, nds, 3ds had it's competitors ( like windows have linux as enemy).
On switch, Nintendo literally has no competitor portable console.
My guess is that they will launch some fancy stuff to mantain nintendo switch portable, and only mess with the dock. Maybe a dock that expands processing power trough usb-c connection (like external gpu).
Line:
Switch lite
nintendo switch 'normal'
nintendo switch pro-dock (switch normal compatible only)-dlss, 4k connection, not close to ps5 or xbox series s, but at least 60fps 1080p capable or 4k-30 on some titles.
My second guess is a switch that has no portable mode.
Line would go
switch lite (only portable)
switch normal (portable or conect on tv)
new nintendo super switch advance sp (only tv connection). In this case, i think maybe xbox series s like poerformance. (300 dolars, and price reducing on other models)