I don't think this kind of comment is very useful, to be frank.

Of course you can use TWOV (24hrs) to arrive in one city, then fly to another city within China, then continue to another country. In fact you could take as much domestic flights within 24hrs as you like.

Regarding the original question, if that's on one ticket and without luggage AND especially if there is a later CAN-WUH flight that would still allow the connection to the WUH-NYC flight I could imagine trying it myself. If CAN-WUH is the only option, I'd not try it. Also, if luggage is included I'd not try it. Just as well as on separate tickets.

The issue I can see here isn't about getting TWOV - that will work - but about actually getting TWOV in time. If there isn't any queue, he'll most probably get it rather quick (boarding pass in hand will make ANY questions go away quickly) BUT if there is a queue, he'll have to queue jump to have a chance at making it. And obviously a reasonable on-time arrival (possible, but not guaranteed)

Problem is, if he doesn't arrive on time, ie say he lands with 1hr delay, he'll basically not have a valid schedule to continue his journey, which TWOV absolutely needs. So they could ask him to rebook BEFORE being able to get landside. (That's why I kinda felt the urge to strongly ask for a later CAN-WUH option that still catches the international flight) And only once the rebooking would result in a TWOV-compliant schedule being able to continue.

All in all, I'd definitely NOT suggest to do it. But it's possible if you're willing to gamble and/or have alternatives ready.