If someone wants to be the opposite of their exterior physical sex and gender role, that's... trans. It just is. It's as simple as that. Doesn't matter how long the feelings last (or indeed if it's inspired by a trend) or if it accompanies a fetish. Sometimes the fetish is itself defined by pleasure from the alleviation of dysphoric pain. And you know what? It's valid. You're valid. I'm valid. The Hero is valid. We all are OK. If those feelings come and however long they last or however connected they are to a fetish, you deserve support and you aren't a bad person.
I remember reading a bunch of Ranma 1/2 fan pages back in the mid 90's (anyone remember "Anime Web Turnpike"? ) where trans folk were talking about how uplifting the concept of the "curse" was. That's how a lot of trans folk got interested in anime and manga to begin with. We've always been here, we just usually aren't visible. We just know to keep our heads down because some people reflexively hate us with great intensity. Ironically some of them much younger than us who want to somehow gatekeep us out of a hobby we've had since before they were born.
Frankly, though, I don't have time to live my life in fear. And I sure as hell am not going to let that fear deter me from saying how much I love this manga and am grateful to everyone let me be able to read it. Deeply grateful to the author, the translator, typesetter and so on. Thank you so much! This really made my week and I find it super uplifting.