I think there's an ambiguity here. Let's give names to some more specific things.
Proposition A: "Chromosomes, genitals, and sex hormones are real things. For the large majority of people, each of these falls into one of two fairly well separated classes, and they agree with one another. In some contexts -- e.g., providing someone with medical care, or having sex with them, or predicting how much weight they will be able to lift if they train hard -- these things provide useful information."
Proposition B: "The term 'biological sex' has a clear and universally agreed-on meaning, and refers to something that is useful in some contexts, as in Proposition A."
Proposition C: "The term 'biological sex' has a clear and universally agreed-on meaning, and refers to something that is useful in some contexts, and is the only thing we should care about when deciding whether to refer to someone as a man or a woman, or choosing what pronouns to use for them, or deciding what contests they can enter, what bathrooms they can use, etc."
Proposition A is uncontroversially true, and (I claim) essentially no one disagrees with it.
Proposition B is fairly uncontroversially false, because in fact there isn't a universally-agreed way to decide someone's "biological sex" in complicated cases such as when they have complete androgen insensitivity. But for many purposes it's approximately true.
The bit of Proposition C that goes beyond Proposition B is highly controversial.
I originally took your statements about "biological sex" to be expressing Proposition A. The author of the CNN article is denying Proposition B.
Perhaps you always meant Proposition B (or even Proposition C), in which case I retract my statement that no one disagrees with that, but instead point out the bit of Proposition B that's controversial is not expressing a "fundamental truth" about reproduction but a highly disputable claim about language, and that the further bits of Proposition C that are controversial are again not expressing "fundamental truths" about reproduction but controversial and essentially political claims about how we should relate to people for whom "biological sex" and "gender identity" don't tell a single simple coherent story.