Sometimes after a site launch there are changes that need to be made to a site or new pages which need to be built out. 

There's often other work (like a blog post) that needs to get published which ends up publishing the entire site, including new pages which may not be complete yet. It would be nice to be able to set those pages to a draft state so they're not indexed by search engines or added to a sitemap before they are meant to go live.