Sexuality is not strictly a matter of biology but also of social conditioning. The notion that so-called sexual preference including homosexuality is determined by brain structure alone is 1980's thinking. Today hardly anyone is making that claim in developed countries.
Of course in Iran (and more generally across the global south) liberals will push the old narrative about biological determinism because that's the perfect argument to use in nations where laws are still based upon traditional religious norms i.e. stipulating for strict prohibition of homosexuality. To undermine the traditional posture of society towards homosexuality, local supporters of the globalist agenda will thus resort to the said narrative (as in "these poor people, it's not their fault nor do they really have a choice, how can our laws be so cruel and discriminate against individuals for actions outside their control?").
And as soon as these restrictions are lifted, they'll then shift their discourse to constructivism in order to take aim at hetero-normativity which they will describe as a patriarchal, machismo and homophobic order resulting from structural heterosexual bias in public and private education.
At any rate, whatever an individual's predisposition, the social and cultural context will impact their behaviour. Therefore yes, these school curriculae will have an undeniable impact on those exposed to them, in the very same way as excessive sexualization through the media, omnipresent mass pornography and so on contributed to deregulation of people's sexuality; and in the same way as the western world's so-called "sexual revolution" of the 1960's was not a consequence of genetic mutation but in fact of social engineering (i.e. not even of spontaneous, logical evolution and adaptation of society, but of deliberate manipulation from above).
