he doesn't want the male body because he doesn't want to lose the bonds he formed and be the loner with 0 social skills he were in chapter 1, that's the core of the manga.
anyone is free to connect the dots to create their own constellation of analysis, to me is more about madonna's 'what it feels like for a girl' and be a part of a community, if to you is a trans lesbian story, to me is an anti incel cooptation because it highlights themes like sense of belonging, having friends and being cared for. the gender discussion is reduced to "i'm a man, how could you turn me into a woman" as in the first sense of self, the normality mc had to "i don't want to go back being a man" as in he thinks the way he is now allows him to participate in this community he likes so much. compared to his sexuality, where he says he likes girls only, he doesn't show any strong statement about his gender, only that "being a gyaru is fun", to me it seems he'd be happy having either a male or female body, as long as he could keep the friends he made