Hinaloe

<blockquote>
You no longer have to use this plugin because it was merged to <a href="https://ja.wordpress.org/plugins/public-post-preview/" rel="nofollow ugc">PPP plugin</a> at v2.6.0.
</blockquote>
This plugin send <code>Cache-Control: no-cache, must-revalidate</code> header when show <a href="https://wordpress.org/plugins/public-post-preview/" rel="ugc">public-post-preview</a> post.
In other word, that make skip cache of CDN (like CloudFlare, CloudFront… and other), or Proxy-Cache (Like Nginx). 
So, outside people always can see newest draft, and there is no need extra time to close public draft.
This plugin needs PHP 5.3+
Note: If you’re using CloudFront, you should also use <a href="https://wordpress.org/plugins/c3-cloudfront-clear-cache/" rel="ugc">C3 Cloudfront Cache Controller</a>

Non Cache Public Post Preview

Disable cache when show public post preview post

INVELITY

This plugin allows you to post a preview of any post for anonymous users before publishing it. Have you ever written a post with the help of someone who does not have access to your blog and needed to be able to view the article to comment on it before publishing it and do not want to have access to your blog’s administration? This add-on takes care of this by generating a URL.

Super Public Post Preview

Create and share link to anonymous users for preview any post before it is published.

Non Cache Public Post Preview vs Super Public Post Preview