I think it is just a mere formality to take them out from the list. I presume Wang/Wang will take the spot as they have only one GP assignment.
Wang & Wang are at the top of the replacement list, so theoretically China shouldn't have to send them up against their other top two teams at Cup of China. They could have chosen to wait for W&W to get an invite elsewhere, but I don't think China has anyone else to send. If they did, W&W would probably have taken S&H's spot at SA. So my guess is that currently keeping Sui & Han on the list for Cup of China is about selling tickets to the event.

