Those South Africans who lost their citizenship/nationality when becoming Dutch, are still South African, the South African Supreme Court ruled today. For those who didn’t get a Retention Letter in time and complied with an exception in Dutch law this is excellent news. Congratulations!
For those who by Dutch law were required to lose or relinquish the SA Citizenship upon Dutch naturalisation we will have to await how the Dutch authorities will view this. It is possible that the Dutch authorities will now request you to actively relinquish the SA Citizenship. This will likely be the case for current and future Dutch naturalisation requests.
However, those who already passed the process could be deemed to have done everything in their power at the time to lose/relinquish the other nationality/citizenship and thus the Dutch authorities may leave it at that. If you get any formal communication on this from the Dutch authorities please share with us. We champion multiple nationalities/citizenships.