Michael Hannon notes that public moralists "were forced also to trade the robust natural law tradition for the recently constructed standard of “psychiatric normality...” He clearly sees this as a mistake: he wishes they had stood their ground and defended "natural law," which of course recognizes the natural binary of "male and female".
Hannon says that even the radical queer theory academics like Jonathan Ned Katz, (a radical-left historian of sexuality) now argues that "the heterosexual/homosexual binary is not in nature, but is socially constructed, therefore deconstructable."
So Hannon is saying the same thing as Katz, except for radically different reasons. Katz says the gay/straight binary should be dumped because we are all a LOT kinkier than just two choices. We're polymorphously perverse! Three, four, five, a hundred sexualities! Hannon, in contrast, says that the false gay/straight binary should be abandoned, because the true, natural binary is that we are all "male or female".
Hannon is defending Natural Law and teleology --- the opposite of what you initially supposed.
I saw that after re-reading the entire text. Thanks.