Differences from MicroPython, for those familiar with the latter: https://circuitpython.readthedocs.io/en/latest/README.html#d...

I know CP has it's own internal way of handling interrupts for specific libraries, but I find it odd to think about embedded programming without having direct interrupt support.

CircuitPython is my "go to" for teaching people how to program. I have had so many friends that want to learn how to program, and they always want to learn something "useful" like React first, because that's what people are using at work. But, you have to crawl before you can walk, and the simplicity of a computer without an OS or complicated libraries is a great place to start. Make a light blink. If button is pressed, turn a light on. And before you know it, you can press buttons and have music play, or send a tweet to Twitter, etc. The success rate of getting something working in the first hour is 100%. Meanwhile, everyone that has ignored my advice and jumped right into learning CSS, Javascript, HTML, and React has given up after a month. It's just too much all at once. Microcontrollers are simple, but powerful, and CircuitPython makes it even easier.

Adafruit's tutorials are great. If you know someone who is serious about learning to program, get them all the parts for one of those tutorials. They'll make something cool, and if they need your help, it's just executable pseudocode. Even if you don't know Python, you'll be able to help them with only a tiny bit of reading.

What would be the minimum viable hardware to give someone?

I like the Circuit Playground for getting started: https://learn.adafruit.com/adafruit-circuit-playground-expre...

It has a lot you can do without attaching external devices.

This is fun to play with, but on an M0 you're going to run out of memory before you can do anything too interesting. Maybe on a larger microcontroller it's more usable.

In what concerns Python vs JavaScript on taking over the role of BASIC, I am definitly on the Python camp.