I like to think that MicroPython is more like a base project without a standard hardware library/abstraction layer. CircuitPython took MicroPython and built a hardware abstraction layer on top. It makes hardware level access more standardized and you can take your project to a different microcontroller board. CircuitPython only supports a limited number of boards.

If scripting for microcontrollers become more mainstream, it can enable new applications and use cases that do not require a forced firmware re-flashing to change the code.