Note the wording: "That's a personal choice", "_I_ refuse". Kerr knows perfectly well that people who use gender-identity-based pronouns aren't making a false claim that trans men produce sperm, _&c._! Rather, she's saying that a pronoun convention that groups together females, and a minority of males who wish they were female, affects our cognition about that minority of males in a way that's disadvantageous to Kerr's interests (because she wants to be especially alert to threats posed by males), such that Kerr refuses to comply with that convention in her own speech. (Compare to how a Spanish speaker might refuse to address someone they disrespected as _usted_ because of its connotations, without thereby claiming that using _usted_ would make the sentence literally false.)
Note the wording: "That's a personal choice", "_I_ refuse". Kerr knows perfectly well that people who use gender-identity-based pronouns aren't making a false claim that trans men produce sperm, _&c._! Rather, she's saying that a pronoun convention that groups together females, and a minority of males who wish they were female, affects our cognition about that minority of males in a way that's disadvantageous to Kerr's interests (because she wants to be especially alert to threats posed by males), such that Kerr refuses to comply with that convention in her own speech. (Compare to how a Spanish speaker might refuse to address someone they disrespected as _usted_ because of its connotations, without thereby claiming that using _usted_ would make the sentence literally false.)