During the first week of September we were at the Princess Breakfast in Norway (Epcot) and had turkey sausage patties instead of the pork sausages and bacon. If the server says they don't serve it (like ours did at first), just request he ask the chef for you. He cooked up enough for our table and brought it out himself. My cousin had called ahead for us so knew they did offer the substitution upon request. I guess the server was either new, or he had never had the request before.
I'm not sure if this is the case at other character breakfasts, but this was our experience.
HTH