Unable to change menu items weight when the "system.site.weight_select_max" exceeded and "#pre_render" for "number" element is modified

The trimmed version (crucial for this issue) of \Drupal\Core\Render\Element\Weight::processWeight() looks the following:

    if ($element['#delta'] <= $max_elements) {
      $element['#type'] = 'select';
      $element += $element_info_manager->getInfo('select');
    }
    else {
      $element['#type'] = 'number';
      $element += $element_info_manager->getInfo('number');
    }

Now imagine the case when $element['#delta'] exceeds system.site.weight_select_max so the weight element gets transformed to input[type=number] instead of select. The important part of that transformation is \Drupal\Core\Render\Element\Number::preRenderNumber(), that is declared as one of the #pre_render callbacks for number.

However, the next hook may prevent input[type=number] from being rendered at all and users will see undefined inputs without any attributes (i.e. <input />):

function multiversion_element_info_alter(array &$types) {
  foreach ($types as &$type) {
    if (!isset($type['#pre_render'])) {
      $type['#pre_render'] = [];
    }
    $type['#pre_render'][] = 'multiversion_element_pre_render';
  }
}

*The code above has actually been taken from the multiversion module.

The described behavior is caused by the array concatenation ($element += $element_info_manager->getInfo('number');) that adds only the values the keys of which are missing in the initial array.