How to call CLI command via Cron file and pass an object as param

Put this code in your cron file

/**
 * @var \Magento\Framework\Serialize\SerializerInterface
 */
private $serializer;

/**
 * @var \Magento\Catalog\Model\ResourceModel\Product\CollectionFactory
 */
private $productCollectionFactory;

public function __construct(
    \Magento\Framework\Serialize\SerializerInterface $serializer,
    \Magento\Catalog\Model\ResourceModel\Product\CollectionFactory $productCollectionFactory
) {
    $this->serializer               = $serializer;
    $this->productCollectionFactory = $productCollectionFactory;
}

public function execute()
{
    $collection = $this->productCollectionFactory->create();
    $collection->addAttributeToSelect('*');
    $collection = $this->serializer->serialize($collection);
    //Set you CLI command here and pass product collection array in the --collection argument
    system('php bin/magento customer:product:update --collection='.escapeshellarg($collection));

}

How to get --collection data in CLI file

$collection = $input->getOption(self::COLLECTION_OBJECT);

$collection = $this->serializer->unserialize($collection);