It's highly doubtful, and probably just a coincidence. By comparison, look at Quentin Tarantino and his foot fetishism. I goes out of his way to have his lead actresses show their feet in his movies, and comes up with way to center plot points around their feet being bare. If Shyamalan were a navel fetishist, I think he would go out of his way to do the same with his movies and the actresses in them, not just one scene in two movies.
