I agree, as I hate it when people tell me I "can't" eat 6amiyya with babaghanou or put brown sugar and cinnamon in my pie crust because "that's not how it's done". It may not be traditional, but it's tasty, and as frandroid points out, what's traditional changes over time. That said, I agree that these new creations should not be marketed as authentic or traditional examples of a particular cuisine, or at least not until they become so.

As an aside, koshari is the Egyptian version of an Indian dish. One of my favorite instances of a nontraditional version of a traditional dish is a juice stand in Egypt that sells 3aSeer Hohos, as in Hohos the snack food. In this case, I don't actually like the drink itself, but the idea.