Physically owned gold bullion is immune to the electronic financial system. Iran already trades in gold. The banning of Iran reduces the trustworthiness of the financial system and the US dollar, increases the value of gold as a reliable currency, and encourages further diversification into alternative currencies by those seeking a refuge from western fiat currencies.
There should be no doubt that China would be taking immediate action to insulate their transactions against any possible interference by SWIFT.
And SWIFT has done irreparable damage to its own business. SWIFT is no longer an impartial and reliable conveyor of international funds.
It is as though rising insecurity of the western world has shaken it into discarding the most fundamental values: trust and reliability. The Taiwanese, and the traditional Chinese culture, uphold these values much more robustly.