Send post changes to set email addresses (not users or subscribers)

You are almost there. You just need to use wp_mail to send emails containing in your array.

Here is how you can achieve that using save_post action hook.

/**
 * To send email on updating your event post
 *
 * @param int $post_id The post ID.
 * @param post $post The post object.
 * @param bool $update Whether this is an existing post being updated or not.
 */
function send_email_on_event_update( $post_id, $post, $update ) {

    $post_type="tribe_events";  // your post type

    // If this isn't a 'tribe_events' post, No need to send emails
    if ( $post_type != $post->post_type ) {
        return;
    }

    // - Now to Send emails

    // first get array of your emails
    $all_emails = get_post_meta($post_id , '_social_services', true); // this is suppose to be variable containing array of emails


    $post_title = get_the_title( $post_id );
    $post_url = get_permalink( $post_id );
    $subject = $post_title;

    $message = "This event has been updated:\n\n";
    $message .= $post_title . ": " . $post_url;
    $message .= "keep adding what ever you want to send in this email...";


    // Send email to $all_emails.
    wp_mail( $all_emails, $subject, $message );

}
// have kept the priority to 11 to make sure we get the content for email after every thing is saved
add_action( 'save_post', 'send_email_on_event_update', 11, 3 ); 

Haven’t test this code yet. But I’m sure this would work for you.