Required? Not always. But a show like Star Trek should always be moving forward and not get mired in the past.
Treks been over writing data points since day two. If it didn't work, it got dumped. The fans cherish the data points more than the creators ever did.
Indeed, a lot of online fans act as though ST episodes are supposed to be dramatizations of a Wikipedia entry rather than, y'know, works of art in their own right.