I am 99% sure this is dubious and illegal. Digital distribution channels for some games are possible like Egg Music, but they receive endorsement from composers and game companies. This hasn't received any endorsement and I'd doubt Nintendo would allow their music to be presented through this medium. The whole idea of making these releases according to fans' advice also sounds unlikely given just how precise composers and companies are about digital releases. Furthermore, I think the idea of obtaining mass licenses for wildly divergent games is very unlikely too, unless one is a legal and licensing genius with multilingual skills and endless contacts. So I'd recommend either to present the legitimate documents or never bother the official soundtrack community again.
EDIT: And have you seen
his site? Get this soundtrack free after making a personal donation to him? It's totally dishonest and misleading guy like him that are the very worst of the underground VGM community. Tasteless background music too.