Uncommon, staoth infgredients are a bad idea from allergy perspective as well. While beef and pork allergies are not common . . . dietary choices abound that involve not eating red meats for various reasons.
You will possibly (read "quite probably) encounter enraged customer or two, and possibly even an enthusiastic attorney representing one or more of them. People really do hate that sort of surprise . . . advertise it clearly, and you will be much more appreciated.