Donkey Kong Country: Tropical Freeze - file size, preload live in Japan

Nintendo has added Funky Kong to Donkey Kong Country: Tropical Freeze. One would think the addition of content would make for a larger file size in this Switch re-release, even if it's just a minuscule amount. That's what makes this next bit of into a real head-scratcher. Tropical Freeze took up 11.4GB on Wii U, but the Switch version is just 6.6GB. We have absolutely zero explanation as for why the file size is considerably lower. All we know is that the eShop listing states 6.6GB, and the game is available to preload in Japan right now!