OK. Yes. I see that in the book.
– I need to spend some time to find a reference in the Tipitaka. Bhikkhu Bodhi’s book is a translation of a Commentary and is not part of the Tipitaka. Yet, the material in the book is mostly correct.
As I remember, “itthi gati” and “purisa gati” do not necessarily have to match sex.
– For example, there are men with “feminine gati” and vice versa.
– So, even though Brahmas do not have sex organs, they may have different types of gati.
– I think it was Waharaka Theor who explained this in one of his discourses. Anyway, if I find a reference I will post it.
Regarding the other issue, I have never stated that sex change is not possible.
– When a human gandhabba is born by kammic energy, it will have either male or female sex organs (more correctly the blueprint for it). So, when it gets into a womb and is born a human baby it will have either male or female sex organs.
– However, that sex can change even during a lifetime as a kamma vipaka. There is a dramatic account in the Tipitaka of a wealthy person during the time of the Buddha who became a woman and switched back again to a man. He had seen an Arahant taking a bath in a river. That Arahant had a beautiful body and this person generated lustful thoughts and instantly became a woman (of course, he did not know it was an Arahant). After becoming a woman he realized what happened and was able to meet the Arahant and get the sex changed reversed!
– I don’t remember the name of the sutta. Hopefully, someone will know and post the name of the sutta.