I made very small contributions to Yuzu (switch emulator), and there's an extremely strict anti-piracy stance to the entire dev process.

The entire dev discord is entirely anti-piracy as well. Anything linking the source code to pirated code would "taint" the whole project legally.

So while you can theoretically read those leaks on your own and use that acquired knowledge to contribute to the project, there has to be a hard stance against tainted contributions to protect the project legally.