Yes, it does. It's a reimplementation. URDE is a Metroid Prime reimplementation, and they distribute it with NO assets, you have to provide your Metroid Prime assets yourself. After you do that, you can have Metroid Prime running natively on your PC. This is the same thing. Reimplementations are a common thing in gaming and are 100% legal. There's also a Jedi Outcast reimplementation that allows you to run the game at high resolutions and such, for example. Again, no assets included. You provide the assets yourself. 100% legal.
This it the same thing. Again, what has LEAKED is both the source code with NO assets, and a compiled .exe with all the assets. The fact that a compiled .exe with assets has leaked, I repeat, doesn't mean that the developerrs wanted to distribute the game that way, since it's a LEAK.