Unless this is just about menus listing ingredients, that will almost certainly happen. There are people allergic to all sorts of things. Nearly everything is allergen to someone.
Here in Europe there is a list of the 14 most common allergenes and they have to be listed on the menu. Yes, there are people with uncommon allergies, but the majority of people have one of the common ones and they can be on the menu.
Unless this is just about menus listing ingredients, that will almost certainly happen. There are people allergic to all sorts of things. Nearly everything is allergen to someone.
Here in Europe there is a list of the 14 most common allergenes and they have to be listed on the menu. Yes, there are people with uncommon allergies, but the majority of people have one of the common ones and they can be on the menu.