The original question related to people with accounts funded by a foreign credit card. Why should the CCP care about such people being able to spend outside the PRC mainland?
They can just limit transfers between mainland residents and "tourist" accounts.
I think the point is that the government has put pressure on AliPay and WeChat pay to accept foreign cards to make it easier for foreigners to use the domestic payment systems in the motherland, and someone somewhere is swallowing the merchant fees involved.
There is no reason for them to extend this service outside the motherland and bankroll more merchant fees because the original payment card (Visa/MC/etc) can just be used natively or via other payment mechanisms like Apple or Google Pay.