There are actually dozens of WoW private server implementations (called cores) on github, for every version of the game. Their patches will be immensely useful to the various vanilla cores to improve their out of the box support, but this is actually the second shutdown server this year that is dumping its full scripting as open source after a server called Sunwell did it for WoW 3.3, and those scripts produced a dramatic increase in quality among other servers at that version very quickly.