Black swan event takes place in a short time frame. It's an instant event that happens and then a reaction / attempt to fix & recover. But in the case of cbdc a black swan event won't cut it. You can't just impose cbdc on people no matter how serious the event is imo. So what is needed is a black swan ballad, something that takes place over many years and conditions people so much so that they will see cbdc as their best chance of survival when the time comes and adopt it voluntarily so to speak. They may even introduce a gold standard and in a terrible manner so it fails as part of the process.
Tl;Dr cbdcs are still a long ways away. The logistics and scale of something like that is almost impossible, but also if it was possible the willingness of ppl to adopt it, the incentives for the people to adopt are not immediately clear to me yet.