Yes, the trans Vivian thing seems to have two sources. 1)Leftist rumors fueled by what they want to be true, and 2) The Italian Translation, which was clearly an activist translation that took substantial liberties with the script. Notice how all the citations are trashy blog posts from gaming rags from the last five years, and the only references from the gamecube era are in reference to the Italian translation.

This whole thing is mostly based on people who don't speak Japanese telling each other with confidence that Vivian is super, for sure, definitely trans in the original script, and taking it as fact, and that Nintendo has censored their trans representation, rather than a Japanese style femboy of the sort you'd see in a cheesy anime.