Does a folder in my user site conflict with a project site?

I just did the experiment of naming a new repo with the same name as a subfolder in my user site repo:

As a result the new repo took precedence over my personal site.

Github support response:

Yes, they would conflict. The url for Project sites will be username.github.io/project, and the url for a folder in a user or organization site would be username.github.io/project.

I would recommend that you either rename the directory or the repository name.