Remove/Disable "Automatically add new top-level pages to this menu"

Question

Is there any way to disable or remove the "Auto add pages - Automatically add new top-level pages to this menu" functionality via a theme?

I suppose I could hide it with a bit of CSS, but I'd rather do more cleanly if possible.

Many clients click that not realizing what it does and chaos ensues.

Answer 1

Since there is no filter to remove this option, your best best to to stick to using CSS by putting the following in your child theme's functions.php:

add_action( 'admin_head', 'wpse_225635_menu_css' );
function wpse_225635_menu_css() {
    global $pagenow;
    if ( $pagenow == 'nav-menus.php' ) {
        ?>
        <style type="text/css">
        .auto-add-pages {
            display: none;
        }
        </style>
        <?php
    }
}

Answer 2

As per comments and verifiable in the source:

<dl class="auto-add-pages">
    <dt class="howto"><?php _e( 'Auto add pages' ); ?></dt>
    <dd class="checkbox-input"><input type="checkbox"<?php checked( $auto_add ); ?> name="auto-add-pages" id="auto-add-pages" value="1" /> <label for="auto-add-pages"><?php printf( __('Automatically add new top-level pages to this menu' ), esc_url( admin_url( 'edit.php?post_type=page' ) ) ); ?></label></dd>
</dl>

there is no filter to get rid of Auto Add Pages in a clean way. You'll have to use css or javascript.