I just called into Citi, trying to convert a MIleUp card to Double Cash. Rep said the conversion isn't available, and told me to try again in a month. Tried a different rep as well as a different citi card, no dice.

Does anyone know if Citi periodically remove certain cards from the list of available product change options? Or could it be a one-time thing, because of upcoming changes to the Double Cash card's reward rules?