I use some plugins to dynamically include content into a page via shortcode, such as "List category posts" plugin where I enter a shortcode like [catlist id=25], and that is rendered into a listing of post titles.
That shortcode should NEVER be picked as a "keyword", at the bare minimum!
It would be super cool though to maybe be able to click a button on the page/post edit page, and have the plugin parse the shortcode and then pull they keywords from the returned dynamic content.