Just saw some information on this and found out
CosmoCortney was the creator of this and... that explains a lot. They were one of the first people to write hacks for Breath of the Wild on Wii U. Tons of crazy stuff on their youtube channel up this alley, as well. This reminds me a lot of The Wind Waker Repainted, where a team of streamers basically just replaced most of the in-game textures with random pictures (mostly memes) and just did a playthrough with it. But that was purely cosmetic, this actually affects the actual gameplay and it's amazing.