One two hour movie and three, four or seven years of a series are vastly different things. If we all wanted to, we could discuss each and every one hour episode, every character and actor who played them, themes, influence and on and on. Each series is full of its own unique and vast areas to explore. I've been around Trek message boards a long time, and even ones that have existed for many years have yet to run out of topic ideas on a particular series. I doubt a message board designed around one movie is going to use up all the potential threads by December. Anyway, it's an organizational point, hardly anything to get concerned about. Every Star Trek board I've ever visited is organized just this way. It feels very familiar and easy to navigate.
The needs of the many outweigh the needs of the few, or the one.