It is a figure or speech. It does not mean anything. Actual implementation will be decided later. I think most people are in favor of leaving a bitcoin where it is and using a different denomination, like a microbitcoin, as the default.
A figure of speech a simile or a metaphor, or some thing not meant to be taken literally. The way it is written is not figurative.
Yes, it's not set in stone, but it is still a possibility that is being discussed seriously. And considering transferring "0.00000001" bitcoins would turn people away, and there is no real reason not to move the decimal place over, it will probably happen.