Guest authors will never appear when `has_published_posts` user query var is used

The `WP_User_Query` class allows for a query var called `has_published_posts` that accepts an array of post types.

The direct result of using the var is that WordPress will add a sub query that finds all `post_author` values for published posts matching the post types to the WHERE clause.

The post_author column is of course the actual author, not the ones assigned via this plugin, so guest authors will never be returned in this instance.

Ideally we can find a way to make this work how you'd expect.

As it stands this is resulting in SEO plugins like Yoast exclude all guest authors from the author sitemaps.