Documentation for Drupal 7 varnish module may be wrong?

The module installation page suggests that page_cache_invoke_hooks be set to FALSE or otherwise Drupal does not cache.
Based on my experiments, this flag tells drupal to invoke hook_boot and hook_exit when servinge a page from cache.
The relevant code resides in function _drupal_bootstrap_page_cache() and is

    // If the skipping of the bootstrap hooks is not enforced, call
      // hook_boot.
      if (variable_get('page_cache_invoke_hooks', TRUE)) {
        bootstrap_invoke_all('boot');
      }
      drupal_serve_page_from_cache($cache);
      // If the skipping of the bootstrap hooks is not enforced, call
      // hook_exit.
      if (variable_get('page_cache_invoke_hooks', TRUE)) {
        bootstrap_invoke_all('exit');
      }

In other words, you can set 'page_cache_invoke_hooks' to TRUE and still serve pages from cache_page.
Unless this is specific to varnish then I do not see how this documentation is relevant.