Earlier quoted context omitted.
Where? Right now you have "An anonymous person says that an anonymous person said this to him in an email". That's a pretty low bar for "produced the actual voice artist".
To the Washington Post, which verified it. The Post doesn't much care if you can verify their work, because no reasonable person believes they're making this up.
- "The agent said the actress confirmed..."
- "In a statement from the actress provided by the agent..."
The WaPo hasn't spoken to or verified who the voice actor is.