Imagine if the entire game we've been playing has actually been miniature sized... and the DLC will bring the addition of 'the outside world'.
Upon starting the DLC, a huge boom is heard in the distance. Link investigates. Que cutscene of a huge Godzilla-like bokoblin towering over a nearby mountain. It's later revealed that this bokoblin is in fact normal sized.
Link will then have a memory trigger where he realises he's actually stuck in a tiny version of hyrule and needs to find a way to get out and become normal sized again. All the characters in this tiny version of hyrule have been a lie and merely taking on the appearance of those real people in links memory, who all await in the outside world - that's why the voice acting has been pretty bad, because the characters in this tiny hyrule didn't quite nail the real voices.
Once link finds a way out and becomes normal sized again, the 'real' challenge awaits aka normal sized ganon, who in this tiny world, would be fuckin HUMONGOUS.
Imagine.