They will change the scoop for you and they have a list behind the counter of all the flavors without gluten. There are a few flavors on the list ex. blue moon that I personally can not eat. There are others like exhausted parent and the lemon poppy which have been safe so far. I wouldn't bother ordering a gluten-free ice cream cake. It is just ice cream and whip cream.
In response to the person below who said they will not open a new bucket of ice cream for you, that's a very wasteful request and an absolutely ridiculous expectation!