Yeah I mean I think if Ma Long does keep up his unbelievable form, the Chinese might make an exception and not follow their rule of whoever is ranked top 2 by the June of the year before. I mean as far as I know, that's an internal rule established by China and not by the ITTF. Because I can't really think of any sport within the olympics that is not based on each individual country's own tryouts and own decision of who to send. If that is the case, I wouldn't mind seeing they choose Ma Long instead of either Wang Hao or ZJK.
Honestly I actually think it would be wiser for China to choose Wang Hao over ZJK. I know it would be more fun to see Ma Long and ZJK in the finals, if they both make it, but from a national standpoint, the Chinese team ought to think about who has the most chances of winning first, and in this regard, ZJK has shown a MUCH larger potential to losing to non-Chinese players in the past than Wang Hao or Ma Long has. This year he lost to Seo Hyun Doek in the China Open, Gavlas, Antonin in the English Open, and then Boll in the Qatar Open. That level of uncertainty just makes him a bad choice. The Chinese want to play two players who have significantly different styles of play, therefore if one of them is beaten because he matches up poorly in style against some player, their other player won't lose also because he has the same style as his teammate. Having a penhold and a shakehand would provide the maximum difference in style and would further decrease the chances of both Chinese players being knocked off.