Hiding Page by Title from Editing

You can hide pages using a filter on pre_get_posts. That can be done setting 'post__not_in' argument, but that argument need page ids. And you don’t know the id before the page is created.

For that reason, tou can run an additional query to retrieve the ids based on the titles, or better on the slugs (i.e. ‘post_name’).

add_action('pre_get_posts', 'hide_some_pages');

function hide_some_pages( $query ) {
  if ( ! is_admin() ) return;
  $screen = get_current_screen();
  if ( $query->is_main_query() && $screen->id === 'edit-page' ) {
    // add the post_name of the pages you want to hide
    $hide = array('disclaimer', 'hiddenpage');
    global $wpdb;
    $q = "SELECT ID FROM $wpdb->posts WHERE post_type="page" AND post_name IN (";
    foreach ( $hide as $page ) {
      $q .= $wpdb->prepare('%s,', $page);
    }
    $tohide = $wpdb->get_col( rtrim($q, ',') . ")" );
    if ( ! empty($tohide) ) $query->set('post__not_in', $tohide);
  }
}