I think the *worry* is indeed, unwarranted. It's not a catastrophe if you cannot get reservations at the restaurant of your choice -- there are lots of restaurants, and unless you leave things to the last minute, you can almost always get reservations at some restaurant in the park that you'll be in on a certain day, and even if you do leave things to the last minute, there almost always will be a restaurant somewhere at WDW that has space available for you.