Hi there,
Unfortunately that’s not going to be a feature anytime soon as it’s definitely more suitable for plugin.
Code is code so it really doesn’t matter if it’s added in GP premium or in another plugin.
There are lots of related posts plugins out there already so I would recommend looking for a well coded one with good reviews.
Perhaps Tom’s WP Show Posts would help achieve what you are after as well:
https://wordpress.org/plugins/wp-show-posts/
Let me know if this helps 🙂