I’m not surprised, based on the Twitter replies further up the thread.
However, on the strength of those same replies I would expect existing customers to start to be converted starting in February, so not that long now.
Out of interest, is your new card a shorter expiry date than normal? Santander were issuing Visa cards with expiry dates of around 13 months earlier this year, in preparation for the Mastercard switch. I wonder if NatWest are doing the same?