It seems some of us are missing the implication of the article.
Let's say, for the sake of argument, that there really were a way to negate all advantages a person could be born into. No social networks, no additional wealth, no additional opportunities, etc. A place where everyone is born at 25 at the exact same moment: no friends, no past, no parents, no money. We can call this place 'Equalistan', population 1 million. Now, in Equalistan, there is still random genetic mutation. Some people are taller, some people have working memories that store more information, some have long-term memories that store more information, some solve problems by simple heuristics, some follow bodily signals for cues, etc. There's no such thing as 'smarter' or 'better' at birth in Equalistan, however, because these only make sense in hindsight. Each person in Equalistan just has a different, inherited strategy at living. Everyone just showed up at the same moment, 25 years old, no history, no buddies, but just an inherited genetic toolset.
Now, in Equalistan, there's a test to decide who gets the most resources. However, no one in Equalistan designed this test because, remember, we are making sure no one has any advantage; each person only has an inherited, random strategies from birth. So everyone takes this test and there is then a distribution of resource possession. But here is the upshot. Every person completely deserves the outcome they receive on the test. After all, the only thing being tested was each person's 'merits'. Now the question is, does it ever matter whether people "deserve" the amount of resources they possess?
The article isn't saying so much that meritocracy begets old-school elitism after assortative mating as much as it's saying that meritocracy itself is a terrifying thing. That it may be 100% the truth that people deserve the outcome they receive in life, but, who cares?