Korean here. The law is widely regarded as a failure, as there were lots of backlashes from both the game industry and the citizens. (PC gaming is one of the most important aspects of Korean culture, so regulating it is widely regarded as a dick move, except for old people and parents with kids to send colleges to.) It was announced in June that the government will gradually abolish this law.
Also, the law wasn’t enforced that well. There are still some PC bangs which don’t kick out teenagers late at night, and those fun-hungry high schoolers will always find a loophole for these kinds of stuff. (For example, the law is impossible to enforce in software, because even with online multiplayer games you can easily make a overseas account through a VPN.)