They'll be fine until one day you have a Chavez or a Maduro who decides to go after them to do some "ethnic cleansing".
Agreed these folks are probably on borrowed time.
Most of them have gotten wealthy enough that they have second homes outside the country.
They could bail on a few hours notice if necessary.
Another little known fact about South Africa is that whites still own and even run the majority of large businesses in the country.
Needless to say they don’t hold press conferences bragging about it—but leftist black political types have noticed and keep banging the war drums...