Gluten is a common allergen, so there's no need to contact Special Diets. They aren't as helpful as they used to be and will probably just email you a canned response. If a person has more than 3 allergies or uncommon allergies, Special Diets should email you a form and forward that information to the various restaurants since more pre-planning may be required. They don't need to know exactly how many in a party have a particular allergy. The Disney TS restaurants are well-prepared to deal with the common allergies. My kids each have 3 different common food allergies. We note them on the ADRs and haven't bothered contacting Special Diets in the past couple years. The chef comes to the table and asks who has what allergies, lets them know what's safe, writes down their choices, then has the waitperson take everyone else's orders. Chefs have always been helpful, sometimes even going an extra step to make things special for my kids.