Pretty sure Julian was meant to be "androgynous" but just for the record, he has a "smug" personality, indicating that those with that feature will 'flirt' with female players more so than anything. Pretty sure if he was gay he wouldn't be doing that. Whether you would feel it was to "cover up" the fact that he is or not well, that is ultimately for you to decide, but considering Gracie is a boy in Japan and girl in the US version, I wouldn't say it is uncommon for the game to portray such characters. In Japan after all, reverse gender-specific roles are not uncommon. Imo, if Julian were to have a "label" he would be most likely be bisexual if anything. I personally don't believe in "labels" so I personally don't care what he is lol I happen to be straight and like Unicorns so despite what he is, he is a personal fav of mine, and things like "sexuality" matter not to me :3 I find it a tad bit funny that sooo many people like Yoshi, but overlook the fact they call him a "he" when he technically lays eggs AND has a crush on Birdo (Who originally is stated in Japan to be a boy who thinks he is a girl) yet many people are oddly fine with that and don't consider him "gay"
Imo, I feel it is rather childish to "despise" a fictional character just because of their looks and for the fact that they "may or may not" be gay, but hey, whatever floats your boat! This is just my personal opinion as well. Nothing more, nothing less.