"As for people complaining about change in sexuality, if none of you would actually read anything other than manga, you would learn that even in real life, changes in sexuality of trans people is quite common, and that's in real life, when transitioning is done as an adult and via surgery and hormones, while in this manga and most others, the sex change tends to be down to a chromosomal level,
changing completely into a girl."
Amusing. The bolded part is the exact thinking that brought the "heteronormative" up in the previous chapter comments. Ok the change is completely into a girl, so why must the new girl now be attracted to a guy? Can't she be changed into a lesbian? Unless you consider lesbians to be less of a girl than straight/bisexual women.
And also considering what I read a lot of the "change in sexual orientation" is self reported.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0110016 Here is one research. And I'll quote conclusion:
"In line with earlier reports, we reveal that a change in self-reported sexual orientation is frequent and does not solely occur in the context of particular transition events. Transsexual persons that are attracted by individuals of the opposite biological sex are more likely to change sexual orientation.
Qualitative reports suggest that the individual's biography, autogynephilic and autoandrophilic sexual arousal, confusion before and after transitioning, social and self-acceptance, as well as concept of sexual orientation itself may explain this phenomenon."
Another putting things together
https://bit.ly/2L5qjm7
There are more, but I can't be bothered to look for all. Because the fact is "We don't know exactly.". Claiming that "Sexual Orientation SHOULD change, because of hormones." Is just self serving. As it's equally valid for sexuality not to change. We have example in the world for all the cases.
And finally if you think "well the change is complete, the new girl is completely a girl, in mind, body and soul, so she should be attracted to guys." IS heteronormative. That was the whole point of that.
Honestly my point is, please stop bringing biology up for why things SHOULD be in a manga, or "it makes sense to go this way.", or any other justification. When reality is, it doesn't matter. If a story wants to write a Idol Pretender type story, where the changed is now attracted to guys. Or if the story wants to be about the changed still only being attracted to girls. They can both be valid and plausible. Regardless if they are about magic or "science" type changes.