A comment was made earlier that the revision of the meaning of marriage to incorporate SSM will see minimal changes in school, such as the adoption of slightly different definition of marriage. I think that greatly underestimates what’s ahead.
While it’s true that we are already seeing some push to ‘educate’ children about sexuality beyond the sexual relationship of a man and a woman, it is - IMHO - inconceivable that a decision to incorporate same sex sexual relationships into the societally endorsed institution of marriage will not turbo charge that trend.
From the document in the OP:
“If the law is to declare that there is no difference between marriage between two people of the opposite sex and marriage between two people of the same sex, then sex education will be amended to teach that all forms of sexual activity are equal. This will result in sex education becoming more complex and detailed, and not simply an explanation of “the birds and the bees.”
"Sex education was expanded in Canada following the legislation of SSM. An early decision of the Canadian Supreme Court related to the introduction of books in the kindergarten – year one curriculum portraying same-sex couples. 83 The Supreme Court ruled that it was in the interest of same-sex parented families and the children who belong to them to receive “equal recognition and respect” in the school system. When parents objected on the basis that the material was not age-appropriate, the
Court responded that “tolerance is always age appropriate.”
"Just over 10 years later, the required education was expanded from family structure to sexual activity. All schools – including religious schools – are now forced to teach year three students a sex education curriculum introducing homosexuality, and year seven students the specifics of homosexual sex ."
Canada - Updated Sex Education
Similar directions are evident in the UK with a teacher union campaigning for comprehensive age-appropriate content including promotion of LGBT+ matters… and expressing a view that exemptions for faith-based schools are a dangerous loophole.
UK - Teach Toddlers about Transgender et al
And here is the thinking of some activists in Australia
Aust - Sex Ed Fails Queer Students
While many may think this is an unlikely directly for Australian schools to take - I don’t understand on what logical basis society could on the one hand say that marriage includes SSM, and on the other hand, not adjust sex educational programs accordingly.