Unless I am missing something here why would anyone in China want a .io address?
It belongs to the British Indian Ocean Territory.
It always boggles me when I see someone using .ca (canada) as a california domain.
Same as .co it will always be Columbia and sure I will take it if nothing else is available but the .com is still the king.
I don't think I would ever use another country's code as a domain for my business. It just sits wrong with me, cannot describe it but I guess as close as I can come is it feels like I've adopted a domain name from a different country.
Before I begin let me be clear that I don't do the China stuff for the most part. So I'm giving my opinion based on reading/listening.
I think the investor side speculation craze is drying out a bit in China .. in part because of those left holding the bag with crazy p2p loans likely are still feeling the burn. But also simply because Chinese domainers are getting smarter and starting to focus on domains that could actually end up with end users one day! lol
I think they could very well look at NNN.io and maybe LL.io .. but likely not so much for anything else.
We need to keep in mind that a bunch of new TLD's are becoming "legal" in China .. so demand for non-.com and non-.cn will be diluted .. and since that market is already softening I wouldn't be too hopeful on anything else really taking off there for a while.
So aside from those super short I mentioned, I wouldn't touch stuff like geo-pinyin with maybe the exception of the biggest cities .. and even then I personally wouldn't touch them because of the holding costs of .io
That's probably the biggest reason it probably won't take off there .. as the Chinese aren't used to high holding costs ... their .cn costs a fraction of other ccTLD's.
If you want a repurposed ccTLD for China, I think .cc is still the most used alternative after .cn/.com .. not 100% on that though.