How can I force a customer reset his password programmatically for Magento 2
You can call ‘initiatePasswordReset’ to force Magento 2 reset their password programmatically.
$email = "demo@demo.com";
$object = \Magento\Framework\App\ObjectManager::getInstance();
$customerAccountManagement = $object->get('Magento\Customer\Model\AccountManagement');
$customerAccountManagement->initiatePasswordReset(
$email,
AccountManagement::EMAIL_RESET
);