Edit: Haupt was "coloured" not "black", a very important difference explained in an answer by u/khosikulu below
I found very little information on the Clive Haupt, only that he was a 24 year old "a coloured man who had collapsed on a Cape Town beach the day before" according to Wikipedia. According to this stub from the History Engine of University of Richmond he Blaiberg was buried in an all white cementary and this was according to this site a " cause of celebration because it was illegal for “coloreds” to be buried in the same cemeteries as whites " The Wiki also says "That the identity of the heart donor had been released led to much heated controversy in South Africa."
This is understandable of course, but what I'm wondering is if there wasn't much more controversy about the ethics of the obvious use of racial power at play here, where a black mans body was used without consent (I would assume so at least, considering it's Apartheid) to extend the life of a white man. So how did people react to this? Was it seen as "noble" or as a humiliation? Or as something else completely? Would it later "normal" for black peoples bodies to be used as organ donors for whites in South Africa? Was there awareness of this practice and was it really a "cause of celebration" or was there also (black) resistance to this?
There is an important clarification to make, first and foremost. In the context of South Africa in the last century, "Coloured" is not "Black," either by the logics of apartheid or internal group identity. These are notionally separate groups, despite some alliances and parallels, and not simply interchangeable labels. The former was considered part of South Africa by apartheid ideology (as people of mixed heritage that was Khoe, Asian, European, and only sometimes other African, rooted in the Dutch era) while the latter group was soon to be entirely denationalized and stripped of citizenship with their assignment to 'homelands' under the relevant Act of 1970. This is important to understanding here, because Coloured people retained key rights, and the degree of the transgression to racial ideologues was not the same as with another African considered Black (or Bantu, 'Native,' or whatever other name used). So to an important degree we can separate those concerns within SA itself, although it wasn't always seen that same way outside of SA, as Maya Koretzky notes in her 2017 Social History of Medicine article.
In the same essay, Koretzky notes that Haupt's wife and mother were both at his bedside and consented to the transplant. SA media thus often framed it as a selfless act across the color line and a triumph of technology, despite voices opposing it. Outside SA, it was often read as a sort of banditry. Her essay is worth reading beyond the South African situation; it also touches on the context of other interracial heart transplants of the era elsewhere, as well as other details of the Haupt case. Because Haupt was Coloured (and his kin gave consent) it did not carry the same array of meanings (and menaces) to different identity groups as a transplant from a Black man would. [eta: Blaiberg also consented, and banked a bit on his fame while trying to portray neutrality, although of course critiques did swirl around the two's widely different statuses in class and SA's racist system.]
See: Koretzky, Maya Overby. "‘A Change of Heart’: Racial Politics, Scientific Metaphor and Coverage of 1968 Interracial Heart Transplants in the African American Press." Social History of Medicine 30, no. 2 (2017): 408-428. Open Access here
[edit: I had to rush this--I may add more once I have access to my other books, but Koretzky and her footnotes are a good place to start for sure--and others no doubt can add a lot more on broader questions, etc., and particularly the question of burial which is one I don't really know the particulars of.]
Black South Africans didn’t even have basic human rights during Apartheid and wouldn’t have had much say if a heart from black person was used (with or without permission) in a transplant.