This is effectively a pandora’s box now where that code will be like a multi-headed hydra. The server side source isn’t as huge compared to the distribution of the game client (which has more of the visible intellectual property). It will be interesting to see how NCSoft handles this and what (if any) precedent happens going forward.
UPDATE: MassivelyOP posted a follow-on article that contains a Q&A with the lead SCORE developer. The most telling is that he couldn’t provide detailed answers with regards to collaboration with former developers. So it’s highly unlikely the server code was initially clean room reverse engineered. It would’ve probably been wiser for Leandro (the lead dev of the project) to retain some form of legal counsel before commenting since NCSoft could end up deciding to file a copyright infringement lawsuit and subpeona individuals to find out who those former developers were.
While nowhere close to the former Lineage III development team that left to form Bluehole Studio (and who then ended up using misappropriated intellectual property from that project for what became TERA), it would still be considered a breach by NCSoft. I’m no fan of them but I also understand the need for these companies to protect their intellectual property. But I’m also a believer that these companies (whom are now offering most of their titles as “games as a service”) should also offer a sanctioned way to play even if in limited form (like local server binaries that allow the game client to continue operating in this offline mode as well as the players ability to download their character data for use in that offline mode).