All art and content reflects the political worldviews of the author, even if they don't intend it, but the author can also be cognisant of those views and decide to express them in a more active fashion. This is neither good or bad, after all Miyazaki's movies are a good example of active political messaging, but still restrained enough that the average person could still miss it completely (somehow). The real danger lies in the moment an author flies a little too close to the sun with their messaging, typically because without proper setup these ideas can feel very alien in what was a previously fictional world.
I mention fire force because it's probably the perfect example of an author expressing an opinion so brazenly with a stereotypical "strawman + le epic logical debate bro" scenario that even the average less critically-minded readers were wondering what the hell was going on. If even your most unengaged readers are asking "what's bro yapping about??" you know you've probably gone too far lol. It was plastered everywhere in magna/meme communties so look it up if you're curious.
Tbh I think the works where authors put their political worldviews are the most interesting, because it is more honest than your average corporate avengers' movie, about everything and nothing. Even if the worldviews themselves suck, at least it gives space for conversation.
I didn't take part in any of the community talks about fire force as i've read it all the month it finished, and tbh i just don't remember my impressions about author's opinions, other than
something something souls became everything and
ugly d3 became glorious anime and that
wait, dude doesn't look like death the kid. I either didn't get that commentary that you mention, or forgot it.
As I said, this chapter wasn't as bad as that, I was just using it as a worst-case measuring stick. Now I should mentioned when I say "author-insert" I mean both obviously-the-author characters and character dialogue/plot that feels like the author leaked something a little too "real" into, i.e. they inserted something they wanted to express into dialogue. I admit this might sound a little stupid since they obviously write all the dialogue, but there is a difference.
This isn't stupid and i understand, I think real-relatable is very digestible explanation why this chapter is so controversial, but apart from the absurdity of the sickness, the rest of the manga has been mostly real - real.
I think that honesty (or lack of irony, or any symbolism that author could use as a shield) is something that make story like this more worth-reading. As a comedy it is just mid, and "I am suddenly wo/man" is a very oversaturated genre. I think the reason why most of us finds this manga intriguing, despite that cliché, is that lack of caricatures and author's aim to distance themselves from their story. I think it's more a matter of loosing lightheartedness from previous chapters, rather than gaining reality.
The questions that i still have are basically:
Is this manga main aim to be antitrans?
Is mom's opinion author's opinion? Or is it plot device to force MC to explore their new body.
Even if mom's opinions echo the opinions of the author, does it make him/her antitrans? Or just insensitive.
If the main character decides to not go through the surgery, does it make this manga antitrans?