A Switch plus, but with a new chip, not exactly the X2
NVidia makes a new Shield Android TV every 2 years and will need new hardware next year. Since both Switch and Shield use the same hardware, there will be something coming next year unless Covid delayed it's development. My expectations are a switch to A75 or Carmel for the CPU and Turing GTX (No tensor cores) for the GPU (Ampere is too much of a power hog for such tiny devices and Pascal too old by now), combined with 8GB RAM on a 128 bit bus.
In other words, a somewhat modernized X2. The alternative would be to reuse the X2, but produce it in a 12 nm process, which would result in it consuming less power and producing less heat.
The Nintendo eShop rating Thread: http://gamrconnect.vgchartz.com/thread.php?id=237454