Not necessarily. So far as I know the bible doesn’t mention continents besides Europe, Africa, and Asia. That doesn’t mean they don’t exist or that they’re presumed not to exist.
It just means they weren’t central to the message.
That means that the message could ignore them, and that the readers could too....even though they didn’t know them to be able to ignore them.
I never said they didn’t exist, I said the writer had no idea that they did.