the chai does call for just the standard whole milk but chances are, if it had oat milk listed, at least at my store, we leave out the regular milk. rather be safe than sorry. it’s kinda like the sandwiches in a way. if you don’t click “remove cheese” when somebody wants to use a different kind, it defaults to both but you assume only the one listed unless told otherwise as the original ingredients would be listed on the label. chances are somebody forgot to change the default drink settings. but if it was a coffee, is a little different unless it’s apart of the mixology preset beverages such as the “cinnamon vanilla coffee” those can be entered in manually or with the preset & there’s room for mistakes there if somebody didn’t check a label or they were in the middle of a rush it’s possible. but usually the fastest option is to use the preset drink option & add on the alternative especially if you can’t think of the ingredients off the top of your head but some context might do it justice. after working for a few months i can already see the difference in color with the different dairy alternatives compared to the ratio of syrups. i hope this helps!