This would allow compiling the Minecraft: Legacy Console Edition source code from newer versions of Visual Studio, expand the Renderer code, add new Input support, etc...

This would also help document the structure of their projects for decompilation projects of newer versions of this version of the game

Does this use leaked code?

No, this does not use any code from the Minecraft: Legacy Console Edition source leak, this is all clean decompilation from binaries and debug binaries