I'm testing the New Blog Templates plugin. It is set to copy pages from a "demo" site to newly generated sites (new client sign-ups).
The New Blog Template IS copying over template files, plugins, etc. (as far as I can tell) but not pages.
To confirm, the demo site is not the main site AND the "What to copy to New Blog" settings include "All Pages".
Example Case: Upon registerting a new site, the only page is a generic "Sample Page". Because the "Home Page" isn't there (which in the demo, is set to the default home page), when the new client visits the site, a 404 error occurs.