They might have a small point in that evolution assumes that human beings, no more than any other individual animal, are not fungible: they each carry different genes that express as varying traits. The latest euphemism, "human biodiversity", is particularly galling gibberish. Biodiversity has an established meaning that you don't get to usurp. Last time I looked, humans were not facing any obvious genetic bottlenecks. There aren't really many that count as relict cultivars of tomatoes or goats. Efforts to preserve diversity in human genomes seem.... unnecessary. When they go extinct, it won't be for lack of genetic diversity; just that intelligent life is a self-limiting phenomenon.

As with much on rationalwiki, it's just dismissive rather than a logical argument or evidence. We have clear evidence of relatively recent genetic influences on human evolution in Lactose Tolerance and both Tibetan and Andean adaptations for high altitude. Not to mention HBD isn't an attempt to "preserve" the diversity but to actually acknowledge it.