These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
They Wasted a Perfectly Good Plot: The film's twist ending renders most of the suspense completely pointless, since it completely removes the supernatural elements. Arguably, it would have been far more interesting had Those We Don't Speak Of become real as a result of the Villagers belief, which would have been more in tone with the rest of the film. Imagine the Oh Crap moment if it instead ended with all of them slowly walking out of the forest, furious that the Villager's had broken the Truce?
The Film's original ending is this too. Imagine the implications of finding out that you live in a completely different time. That your parents have been lying to you for years. That deaths could have been easily prevented. How would you fit into a civilization hundreds of years more advanced with technology you never could have imagined? All of these are interesting premises that never get addressed. There are two very interesting ideas in the ending and neither is used.
Another good way to incorporate the twist is that both the village and Those We Do Not Speak Of are still real, and it's just that the people are still living like it's the 1800s because they've been isolated from the rest of the world since that time.