Right, but their point is that if what the article you link to is true—if 44% of people are right on key when singing a song—then it should also be just a matter of collecting 12 songs with different starting pitches and mapping songs to notes and now you've learned a full scale of absolute pitch.

Few people do this because it's simply not practical, but that 44% of recordings match the pitch of their source exactly shows pretty conclusively that there's nothing magical behind absolute pitch, it's just that most of us learn to associate pitches with songs rather than giving them names.