New post status for custom post type

Register a post status "aggregated" for custom post type "recipes" :

register_post_status( 'aggregated', array(
                    'label'                     => _x( 'Aggregated ', 'post status label', 'plugin-domain' ),
                    'public'                    => true,
                    'label_count'               => _n_noop( 'Aggregated s <span class="count">(%s)</span>', 'Aggregated s <span class="count">(%s)</span>', 'plugin-domain' ),
                    'post_type'                 => array( 'recipes' ), // Define one or more post types the status can be applied to.
                    'show_in_admin_all_list'    => true,
                    'show_in_admin_status_list' => true,
                    'show_in_metabox_dropdown'  => true,
                    'show_in_inline_dropdown'   => true,
                    'dashicon'                  => 'dashicons-businessman',
                ) );

In the "recipes" custom post edit screen's publish metabox, adding the custom post status in the dropdown and change the "Save Draft" button label if the selected post status is "aggregated" :

add_action('admin_footer-post.php',function(){

    global $post;
    $complete = '';
    $label = '';

    if($post->post_type == 'recipes') {

        if ( $post->post_status == 'aggregated' ) {
            $complete = ' selected="selected"';
            $label    = 'Aggregated';
        }

        $script = <<<SD

 
       jQuery(document).ready(function($){
           $("select#post_status").append("<option value="aggregated" '.$complete.'>Aggregated</option>");
           
           if( "{$post->post_status}" == "aggregated" ){
                $("span#post-status-display").html("$label");
                $("input#save-post").val("Save Aggregated");
           }
           var jSelect = $("select#post_status");
                
           $("a.save-post-status").on("click", function(){
                
                if( jSelect.val() == "aggregated" ){
                    
                    $("input#save-post").val("Save Aggregated");
                }
           });
      });
     

SD;

        echo '<script type="text/javascript">' . $script . '</script>';
    }

});

Add the custom post status in the quick edit screen of the custom post admin grid :

add_action('admin_footer-edit.php',function() {
    global $post;
    if( $post->post_status == 'recipes' ) {
        echo "<script>
    jQuery(document).ready( function() {
        jQuery( 'select[name="_status"]' ).append( '<option value="aggregated">Aggregated</option>' );
    });
    </script>";
    }
});

Display the custom post status total in the custom post admin grid :

add_filter( 'display_post_states', function( $statuses ) {
    global $post;

    if( $post->post_type == 'recipes') {
        if ( get_query_var( 'post_status' ) != 'aggregated' ) { // not for pages with all posts of this status
            if ( $post->post_status == 'aggregated' ) {
                return array( 'Aggregated' );
            }
        }
    }
    return $statuses;
});

There is a great Step by Step description on how to do that here http://jamescollings.co.uk/blog/wordpress-create-custom-post-status/

To add your custom post status to the drop-down menue, just add the following to your themes function script:

add_action('admin_footer-post.php', 'jc_append_post_status_list');
function jc_append_post_status_list(){
 global $post;
 $complete = '';
 $label = '';
 if($post->post_type == 'recipes'){
      if($post->post_status == 'aggregated'){
           $complete = ' selected="selected"';
           $label = '<span id="post-status-display"> Aggregated</span>';
      }
      echo '
      <script>
      jQuery(document).ready(function($){
           $("select#post_status").append("<option value="aggregated" '.$complete.'>Aggregated</option>");
           $(".misc-pub-section label").append("'.$label.'");
      });
      </script>
      ';
  }
}

With this you have your custom post status up and running in 5 min, saved me a bunch of time!

Your code should be sound, and should add the desired status to the $wp_post_statuses global array.

If you are expecting it to show up in the admin drop-down, however, this is an ongoing issue: https://core.trac.wordpress.org/ticket/12706