The article states more cases than that. One of the examples the mortgage payments aren’t being made via Chinese wires, they are being paid locally and the Chinese income doesn’t exist at all.

They could be making round trips with Chinese banks but I don’t see why. You can transfer funds from China into your account before your monthly mortgage was due, the mortgage provider would never know. You can also put dollars into a Chinese bank account and do wires in demand, since it isn’t R!B there are no controls on it.