This is not a data leakage.
They deliberately included 999 of their customers' email addresses in publicly accessible JavaScript code in order to test certain features on them.
Certainly that wasn't intentional to broadcast to the public? Sounds like a textbook data leak.
> A data leak is the unauthorized, often unintentional exposure of sensitive, confidential, or personal information to an external party, usually resulting from weak infrastructure, human error, or system errors.
> A data leak is the unauthorized, often unintentional exposure of sensitive, confidential, or personal information to an external party, usually resulting from weak infrastructure, human error, or system errors.