I'll keep correcting this when I see it. There was no Musk-owned, South African Apartheid emerald mine.
It was a mine in Zambia. A completely different exploited African nation. And Musk was only about to afford it because, as a wealthy white man in South Africa benefiting from Apartheid, he had a private plane that he traded for a share in the mine.
The "self-made" man got rich because of colonial exploitation in two African nations. Not just the one.
You say "correct" but you're not contradicting the meme. The reading that "apartheid South African" is referring to the man rather than the mine is to me more intuitive. Even if it wasn't it would be a possible reading, so I don't think you should say you're correcting the meme.
To me, "apartheid South African emerald mine owner" appears to mean that the mine was in South Africa. It does have a bit of ambiguity. I think that it's important to provide enough detail to make the scope of exploitation involved clear. Sometimes it can be simple, like "sweatshop" but, in this case, Musk has invested a lot of energy into his myth of a "self-made" man, especially in suppression of the origins of his wealth that it behooves use of done specificity to demonstrate how rotten even his origins were.
I support the desire to add context the fact you did add. My only concern is that your phrasing comes off as saying the meme is ahistorical or dramatised, when it's probably just the phrasing.
You're absolutely right. My wording is that way intentionally as a bit of a "hook"/humor. Not humor making light of human suffering but to make it bearable to discuss and draw attention to it.