(I haven't been following but nice to see a group release one of these instead of announcing it months before it's done and getting Nintendo'd before any chance to release it into the wild.)
They are not publishing any copyright protected content. Users need to provide their own ROM in order to use it with Nintendo's assets, presumably sourced legally. The project itself does not provide any of these assets.
How is that different from the emulators that Nintendo has shut down?
Nintendo alleged Yuzu was “primarily designed to circumvent several layers of Nintendo Switch encryption so its users can play copyrighted Nintendo games", that's all it took, and isn't that exactly what this is doing? It just happens to be one single game, rather than a large number of them.
Fuck Nintendo. Any bets on how long it will take them to realise piracy is a service problem? I'm setting the over/under at "the heat death of the universe".