I can see the appeal of having an audio "library", and then having just the Events be tournament (or template) specific. But it also would prevent, or greatly diminish, the ability to share those templates. Events that play sounds have to know about the sounds (there's a "link" between the two), and an event that plays a sound isn't much good if the sound isn't there (or the software isn't aware of which sound it should play).
I'm not sure how much effort this would save, anyway. As it is now, if you have multiple Events templates and you decide to add a new audio file to play a some specific point in the tournament, you have to (1) add the audio file itself as a Sound and (2) add or update an event to use that new sound. Of course you will have to do this with all Events templates to which you want to add the sound. With a sound "library", you would have to do step 1 only once, but still have to perform step 2 for all of your templates. Granted, it is fewer steps, but is it that much of a savings?