Listing future posts together with normal posts

Add the post type parameter to your get_posts args.

$args = array(
  'numberposts' => '3', 
  'category' => $category, 
  'post_status' => array('publish', 'future' )
  'post_type' => array('post','slug-for-the-event-manager-post-type')
);

$myposts = get_posts($args);