We do not have to worry about Gluten free dining, but when we went in April we saw 3 or 4 families with this issue and it was awesome to see how Disney handled it. One family we were chatting with said that her two daughters had this allergy and that she was really concerned about going to Disney with this allergy. Once they got there she stated she was on vacation from having to worry about her kids and gluten!!!
The chefs came out at every restaurant and provided information as to what the girls could eat on a buffet, reassured her that they when they prepare Gluten free foods it is in a different station so the food does not even come close to being in contact with the rest of the food. She was absolutely amazed at how much care and concern the restaurants had for their issue and not one time during their stay did they have any issues. She actually felt like she was on a vacation since she didn't have to worry about it at all.
You will have to let them know when making your ADR's and when you check in, but the wait staff also asked as well. We didn't have any allergies and they still asked!