I want to exclude a subfolder from the docs/ directory from generating doc pages. customDocsPath is a related option but it's a string. Is there by any chance some undocumented option that accepts something like a glob pattern?
To formally answer your question, no there isn't an option to do so in Docusaurus V1.
It's unlikely that we will add this into V1 but we would be happy to support that functionality in V2 and add a draft option in the front matter so that it would show up during development but not the production build.