I think Hitchcock would recognise the gates as Macguffins. Consider your classic 'coded diary' Macguffin: it's an artifact of tremendous power, but that power is irrelevant to the story, which is about the interactions between a small group of characters who are chasing and colluding and double-crossing each other around it.
Or the Ring in 'Lord of the Rings'. Artifact capable of enslaving the world. Yeah, yeah, but all it ever actually does, plotwise, is make someone 'invisible' - and even that petty level of power isn't supposed to be used. If the Ring were instead an indestructible cursed Pepsi bottle, the story would be the same.
So far, at least, the gates fall into the same category. They could be nuclear devices, or gemstones that need to be collected by the Four Heroes of Light, or Grape-Flavored Chapsticks of Doom, and the only difference would be a few cosmetic changes to a handful of frames around the things themselves.