There seems to be some confusion regarding East Sea/Sea of Japan issue and IHO’s decision, especially because only Korean media and ROK gov’t are making the fuss over it.
So, a few people have contacted the ministry of foreign affairs and asked what exactly happened. The information [in Japanese] was verified by independent sources.
So, taking that under consideration, here is what I think happened.
South Korea: We are determined to prevent IHO from adopting Sea of Japan! East Sea should be adopted! We gonna beat evil Japan !
South Korea: You know what? We are scared. So we are not going to formally propose East Sea at IHO conference. 
So there was no vote or anything at all.
The chairman: unofficially tells “OK, ok what about taking the name out of the map for now until South Korea, North Korea, and Japan agree on this and publish new 4th edition of the map now?”
Japan: That is not a good idea.
The chairman : OK, ok never mind, forget about it. 
South Korea : We won! IHO proposed to take the name down out of the map! 
Japan: Huh? what are you talking about?
South Korea: Aigo! Oh please god! Japan please please accept pleeease! 
The 3th edition of the map is the official map until the new 4th edition of the map comes out. And 4th edition can not be published because the issue wasn’t even put to vote. That’s all.
The story sounds ugly, but let me remind you that it’s South Korea herself who started, and no one asked South Korea to act this stupidly. Don’t kill the messenger, I’m just describing what I think happened.