According to this, the law "mandates ICASA to regulate historically disadvantaged groups’ equity requirement at no less than 30%", rather than just saying "South Africans": https://www.parliament.gov.za/press-releases/media-statement...

(I would like to link to the actual law, but the URL ChatGPT gave me doesn't load and I don't know if that's because ChatGPT's wrong or the South African government's website is having problems).