I don’t think that statement answers the question.
They don’t say they are not selling the old design anymore, they just say they switched production to the new design.
That doesn’t mean you won’t get the old design when you buy now.
New production means it has been updated already when that post got published, and is its already over month ago, the chances to get old FW16 when ordering now is pretty much close to zero.
The answer was that the manufacturing partner is currently still using liquid metal. The friendly sales person answering said that there is no definite date yet when the transition to PTM will happen.
All new production has been using PTM since early November. There were still units with Liquid Metal in inventory for a period of time, but at this point, new shipments for most if not all system configurations should have PTM.