Carol put in a tremendous amount of work to build tooling to go between Markdown and Docx. The publishers used the docx versions for print.
That doesn’t mean that I think Markdown is inadequate or the wrong decision, but it’s not just a “write in Markdown and you’re good” sort of situation.
I can find here the process of converting docx to md, but not the reverse. I see the material is checked into the repo in both formats. Does that mean the docx's are your master, and you generate the markdown from it for diffing and building HTML?
I'm investigating how to switch an organisation away from a docx-only mess of a documentation system, and it looks like you might have found a process that'd work for us, and let people keep using docx if they have to.
I wonder what all those binary blobs do to the git repo though.
Heck, the Rust book was written with it, and they also made a print edition, so maybe markdown is enough even for that.
https://github.com/rust-lang/mdBook