Visa needed for 2-hour stopover at GuangZhou Airport?

I am flying with my wife from Amsterdam to Guangzhou on Chine Southern Airlines with a stopover in GuangZhou of approximately 2 hours. I am Dutch and my wife is a Thai citizen with a Dutch Residence Permit.

Our itinerary is as follows:
12:30 AMS - 06:45 CAN
08:50 CAN - 10:45 BKK

10:55 BKK - 22.55 CAN
00:05 CAN - 05:55 AMS

Before booking I checked the China Embassy website and it said that :
"A foreign citizen who is transiting through China by air is exempted from a visa if he/she will stay only inside the airport (without entering the boder control) for no more than 24 hours and has a valid connecting ticket with confirmed seat on an international flight."
As we comply with all the above conditions, I booked the flights.

However, I am reading travel reports on the internet now that Thai people in similar circumstances were stopped at Chinese airports and denied boarding because they did not have visas.

I have contacted the Chinese Embassy in the Hague, but instead of answering this straitforward question they referred me to the "Guangzhou Immigration Office."