So following from the comment discussion, a [sufficient answer on another StackEx question][1] goes like this:

    add_filter( 'parse_query', 'exclude_pages_from_admin' );
    function exclude_pages_from_admin($query) {
        global $pagenow,$post_type;
        if (is_admin() && $pagenow=='edit.php' && $post_type =='page') {
            $query->query_vars['post__not_in'] = array('21','22','23');
        }
    }

The only part that's terribly important to us is the array of post IDS.

The problem is that a post on a given installation can have the identical slug, but will normally have a different ID. 

So, what if we create an array of the to-be-excluded post slugs:

    $excludeds = array( 'login', 'logout', 'lostpassword', 'register', 'resetpass' );

    foreach ( $excludeds as $excluded ) {
    
            $excluded_IDs[] = get_page_by_path( $excluded )->ID;
    
    }

This ought to work from installation to installation assuming identically slugged posts/pages:

    add_filter( 'parse_query', 'exclude_pages_from_admin_by_slug' );

    function exclude_pages_from_admin_by_slug( $query ) { 

    global $pagenow, $post_type;

    //set the array of to be excluded slugs
    $excludeds = array( 'login', 'logout', 'lostpassword', 'register', 'resetpass' );

    //get array of IDs from array of slugs
    foreach ( $excludeds as $excluded ) {
    
            $excluded_IDs[] = get_page_by_path( $excluded )->ID;
    
    }

    if ( is_admin() && $pagenow=='edit.php' && $post_type =='page' ) {

        //exclude those IDs from query
        $query->query_vars['post__not_in'] = $excluded_IDs;

    }

Can't vouch for the entirety of the code from testing, and obviously it was meant to answer a different question. Since we don't have alternative code to go on, the only interest here is a model for deriving an array of to-be-excluded IDs and employing it. 


  [1]: https://wordpress.stackexchange.com/questions/13528/hide-a-page-in-the-admin-end-without-a-plugin