Considering how many changes there are, and that Harada WILL fuck around with fans, I'm probably more right. plus, the Tekken wikia has wacky claims about Leo being male like: there is no debate, Leo is male.
I think it's more of the development team trying to keep Leo's actual gender ambiguous because they originally had said that they developed Leo to be liked by fans regardless of gender.
Also, in Tekken posters that show the men and women standing beside each other, wherever Leo is standing, the manual of that Tekken will say the opposite. Namco is pushing the idea "do you like this character regardless o what bio they have?"
Hell, even harada has said in interviews, "Leo is a girl" then immediately right after put Leo's bio as "male"