I actually think the song has lots of potential to be sung with more "gusto" and strength. It's got the right rhythms and build-ups.
Sarah McLachlan - like most singers
- has a definable, trademark sound. So when she sings it, yes, it's sounds rather ethereal and a little softer.
But put a chorus behind the basic track or have a performer with a more forceful delivery, and this can work. You can certainly have this version as well, which is nice. I'm not saying that; it is her song. I'm just saying this could be sung with a lot of power in a stadium and work as a more powerful theme as well. I just wouldn't judge it based on her voice and delivery alone. They may have bolder plans for it as well, and it seems to have the elements that could work for a bigger sound version.