shipping-notifications/ShippingNotifications/Block/ShippingCategory.php

<?php 

namespace Cpcommerce\ShippingNotifications\Block;

use Magento\Catalog\Block\Product\View\Description;
use Magento\Framework\View\Element\Template;
use Magento\Framework\View\Element\Template\Context;
use \Magento\Framework\App\Config\ScopeConfigInterface;

class ShippingCategory extends Template
{
    private $description;
    private $context;
    private $data;
    private $scopeConfig;

    public function __construct(
        Description $description,
        Context $context,
        array $data = [],
        ScopeConfigInterface $scopeConfig
    ) {
        $this->description = $description;
        $this->scopeConfig = $scopeConfig;
        return parent::__construct($context, $data);
    }

    public function getShippingCategory(){
        $_product = $this->description->getProduct();

        $attributeCode = $this->scopeConfig->getValue('cpcommerce_shipping_notifications/general/attribute',\Magento\Store\Model\ScopeInterface::SCOPE_STORE);

        $option_id = $_product->getData($attributeCode);

        return $option_id;
    }

    public function getDelayedShippingCategories(){

        $delayedShipCategs = $this->scopeConfig->getValue('cpcommerce_shipping_notifications/general/shipping_categories',\Magento\Store\Model\ScopeInterface::SCOPE_STORE);

        if(isset($delayedShipCategs)){
            $delayedShipCategsArray = explode(",",$delayedShipCategs);
            return $delayedShipCategsArray;
        }

        return null;
    }

    public function getBlock(){
        $notifBlock = $this->scopeConfig->getValue('cpcommerce_shipping_notifications/general/shipping_notification_block',\Magento\Store\Model\ScopeInterface::SCOPE_STORE);

        if(!isset($notifBlock)){
            return null;
        }

        return $notifBlock;
    }

}