Great stuff but honestly I think this is a mistake:
> Q: Is this a new docs platform?
> A: No, we are working closely together with existing platforms, and our current priority is contributions to MDN Web Docs.
The web needs another platform for this, Mozilla can't be trusted.
You don't have to trust Mozilla. All written MDN content is licensed as CC-BY-SA-2.5, and all code snippets are either CC0 or, for snippets over a decade old, MIT.
And it's all in Git: https://github.com/mdn/content
So if the Web as a whole ever completely loses faith in Mozilla's ability to sustain the MDN platform, all of the content is licensed in such a way as to make it trivial to fork.
There was even an attempt at spinning out the docs ~8 years ago (https://webplatform.org/), which ultimately collapsed back into MDN.