novak1nt

I have figured my issue out. So the problem was where I suspected it, in the wp_query selection. So I had the page echo out the sql query from the wp_query selection like so:

$results = new WP_Query( $coauthor_query );
echo $results->request;

From this I was able to see that the ACF meta_key that I created(coauthor2) is displayed as a serialized Author ID. So here is the update to the query:

$coauthor_query = array(
  'post_type' => 'post',
	'meta_query' => array(
		array(
	    'key' => 'coauthor2',
			'value' => serialize(strval($author->ID)),
			'compare' => 'LIKE'
    )
	)
);

Now on my Authors page. It will display all content posted by the author as well as anything he/she has coauthored.