Recipes do change. At the very least, the ingredients change. Even such stable-seeming items like black pepper are not the same today as they were a year or two ago. And such essentials as seafood and produce change on a daily basis. Indeed, recipes ought to change, to adapt to those variations in ingredients.
Every recipe ought to be tasted every day.
And the way a restaurant operates ought to change, too. When they have to change, they do. Antoine's, for example, is in the avant-garde in its price structure. Proving that yes, things can change when the proprietors really want them to change. Here's a pathetic story I've heard more than a few times in a number of establishments.