Fixing Special Price Date Issues in Magento 2

Magento intentionally hid these values in Enterprise Edition (see vendor/magento/module-catalog-staging/etc/adminhtml/di.xml).

<type name="Magento\Catalog\Ui\DataProvider\Product\Form\Modifier\Eav">
    <arguments>
        <argument name="attributesToEliminate" xsi:type="array">
            <item name="news_from_date" xsi:type="string">news_from_date</item>
            <item name="news_to_date" xsi:type="string">news_to_date</item>
            <item name="custom_design_from" xsi:type="string">custom_design_from</item>
            <item name="custom_design_to" xsi:type="string">custom_design_to</item>
            <item name="special_from_date" xsi:type="string">special_from_date</item>
            <item name="special_to_date" xsi:type="string">special_to_date</item>
        </argument>
    </arguments>
</type>

Per their documentation, they want you to use Scheduled Updates for special price

http://docs.magento.com/m2/ee/user_guide/catalog/product-price-special.html

Its because of Qty and Special Price both are external attributes of product,so if you directly called via $item then you will not get the value for the same

Try below code :

You can get Qty or other values like min qty by using that method.

echo $item->getExtensionAttributes()->getStockItem()->getQty();

OR Complete Object Data

print_r($item->getExtensionAttributes()->getStockItem()->getData());

clear the cache and check it will works.

Update :

Load stock interface , try below code :

 public function __construct(
    \Magento\CatalogInventory\Api\StockStateInterface $stockItem
   )
  {
    $this->stockItem = $stockItem;
  }

 $this->stockItem->getStockQty($product->getId(), $product->getStore()->getWebsiteId());