I entirely agree with you on the first part of this quote. Semenya, Niyonsaba, Wambui, etc, are most definitely women. A complicated situation where it's not wrong to study possible unfair advantages, yes, but that doesn't mean they're all of a sudden men or should be called men. The advantages require study, the fact whether their male of female doesn't, because they're female, that's merely a fact.
Not all African women look the same, obviously. But it's not racist, at all, when one would say it can be difficult to see if a certain athlete (no matter their nationality) is athlete A or athlete B, because both of them have the same nationality (meaning the same colour of clothes), the same haircut, the same length, the same running style etc. In athletics most of these cases happen to be with Kenyan athletes, in cycling it's usually even Dutch athletes I can't tell apart on the TV cameras because with helmets on many of them look alike. If they were wearing the same clothes I couldn't keep Susan Kuijken and Lynsey Sharp apart, merely because they're both as white as snow, both have the same hair (in model, colour, length, everything) and even their faces are alike. In exactly the same way there are (mostly women's distance) races where I find it rather hard to tell apart one Kenyan from another.
Yes, racism and everything is a problem, entirely agreed. It's also a problem that (at least in my country) it's become nearly impossible to even talk about it, because a large majority is either on the 'everything is racist' side ("you don't agree with me? Oh you're a filthy racist!!") or on the 'nothing is racist' side ("Saying black people are stupid is not racist, it's normal!"), anything in between is sadly just ignored or put in one of the two sides anyway. Oh well, I guess that's part of today's world: everything is drawn into extremes more and more and even people you basically agree with will accuse you of all kinds of stuff because you're not going far enough.