MAGETWO-96420: [2.3.x] Customer receives newsletter unsubscription email after registering for new account

- Fixed moving subscription status to 'UNCONFIRMED' if a customer was already in 'SUBSCRIBED' status

Author: oksana-kr

app/code/Magento/Newsletter/Model/Subscriber.php

@@ -591,7 +591,12 @@ protected function _updateCustomerSubscription($customerId, $subscribe)
             if (AccountManagementInterface::ACCOUNT_CONFIRMATION_REQUIRED
                 == $this->customerAccountManagement->getConfirmationStatus($customerId)
             ) {
-                $status = self::STATUS_UNCONFIRMED;
+                if ($this->getId() && $this->getStatus() == self::STATUS_SUBSCRIBED) {
+                    // if a customer was already subscribed then keep the subscribed
+                    $status = self::STATUS_SUBSCRIBED;
+                } else {
+                    $status = self::STATUS_UNCONFIRMED;
+                }
             } elseif ($isConfirmNeed) {
                 if ($this->getStatus() != self::STATUS_SUBSCRIBED) {
                     $status = self::STATUS_NOT_ACTIVE;