iyb: Pashtus is according to most there is still the Kiyum D’Oraisa on the D’Rabbanan Chiyuv to do it Al HaKos.
There is a very minority Shittah in the Rishonim that Kiddush (and Havdalah!) Al HaKos is D’Oraisa. See Nazir 4a (maybe 5a) and the Rishonim there.