Not Display Product Name in the Email template?

module.xml

    <?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../../../lib/internal/Magento/Framework/Module/etc/module.xsd">
    <module name="Magetrend_Custom" schema_version="2.0.0" setup_version="2.0.0">
        <sequence>
            <module name="Magetrend_Email"/>
        </sequence>
    </module>
</config>

registration.php

 <?php
MagentoFrameworkComponentComponentRegistrar::register(
    MagentoFrameworkComponentComponentRegistrar::MODULE,
    'Magetrend_Custom',
    __DIR__
);

event file C:xampphtdocsmyshopappcodeMagetrendCustometc events.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
    <event name="magetrend_email_collect_additional_vars">
        <observer name="mtemail_custom_var" instance="MagetrendCustomObserverCustomVar"/>
    </event>
</config>

observer file C:xampphtdocsmyshopappcodeMagetrendCustomObserver CustomVar.php

<?php

namespace MagetrendCustomObserver;

class CustomVar implements MagentoFrameworkEventObserverInterface
{
protected $order;

public function __construct(           
    MagentoSalesModelOrder $order  
)
{ 
    $this->order = $order;
}


public function execute(MagentoFrameworkEventObserver $observer)
{       
    $transport = $observer->getTransport();
    $orderId = $observer->getTransport()->getOrderId();
    $order = $this->order->load($orderId);
    $allVisibleItems = $order->getAllVisibleItems();
    $totalItemsCount = count($order->getAllVisibleItems());
    $i = 0;
    foreach ($allVisibleItems as $item)
    {
        if($i == 0){
            $productName = $item->getProduct()->getName();
            break;
        }
        $i++;
    }

    if($totalItemsCount > 1){
        $remainingItems = $totalItemsCount - 1;
        $transport['itemName'] = $productName.' and '.$remainingItems .' more products'; 
    }else{
        $transport['itemName'] = $productName;   
    }
}

}

what is the problem? email template