I don't get the point of this (unless its to make money off the RPi name, and I doubt that given their charitable aims).
There are any number of small boards similar to this, of one kind and another, that already run micropython, or beat this price, or have better peripherals, or better processors, or are better in some other way. There are boards from manufacturers or Ardiuno if you want brand names, or anonymous ones if you want a very low price. In short, I dont see what perceived gap in the market (or educational space, if you are coming from a charitable rather than commercial angle) this is trying to fill.