If a page has no inbound links, it most likely won’t get crawled. But you can ensure it does not by adding a meta tag:
<meta name="robots" content="nofollow, noarchive, noindex" />
If it is crawled and indexed there is a chance of it appearing in search results. That may lead to people visiting an unfinished page, which does not look good for your site. I would prevent any crawling or indexing of WIP.