I reckon they did not require an email address to create an account at the time of the bitcoin cash fork. Nitrogensports only required a username and a password to make a permanent account.
They had my address as well as the addresses of most if not all of their clients. I got emails from them all the time.
I know Nitrogensports did not collect emails before and during the time of the hard fork but started collecting them, but optionally, starting only this year.
However, I might be wrong. You can ask Nitrogensports directly in their thread.