Personally, I believe that neither Revan’s gender nor alignment should be canonized, but if they were to at least make the gender canon, I’d have to vote female. Here’s why.
My main reason for Revan being female is because of the characters of Bastila and Carth. Revan is supposedly 38 by the time of KOTOR 1 (which I find to be weird since everyone keeps calling them "young"), so the 15+ age gap between Revan and Bastila is just weird. Revan and Carth are the same age, so it'd be much more appropriate.
Also, Bastila, I believe, is just too dogmatic. She's young. She's been indoctrinated. I think she'd benefit more from a sister/mother-figure than a love interest, especially considering her being an only child (as far as I know) and the fact that she has mommy issues. Female Revan would help her deal with her strained relationship with her mother until she finds her on Tatooine. And male Revan’s teasing would just get on her nerves and make her close up. In addition, who’s to say that the romance between male Revan and Bastila isn’t because of the bond they share?
As for Carth, let's be honest: a man is not going to soften the character of Carth Onasi. Female Revan and Carth's banter is the highlight of the relationship, and she could not only soften him, but help him learn to trust others again. She could be there to remind him that not everybody is going to betray him. In the game, Carth's development felt a lot more natural with female Revan than with male Revan (which could be due to the option to romance him, but still).
Additionally, Mission is another character who would benefit from Revan being female. Revan and Carth, no matter the gender, are essentially the “parents” of the Ebon Hawk crew, despite not being the oldest. Mission is in dire need of parental figures, and I believe Carth and female Revan would fit that role for her perfectly.
Anyway, I'm curious as to what others think about the issue. I didn't want to make this a poll because I knew people wouldn't give a reasoning to their preference. And honestly, if Revan gets canonized as male, it's not going to be the end of the world. I love the character either way. I just believe that Revan's development, as well as other characters' development, would benefit more if Revan was female. It has less to do with Revan's actual gender and more with how the character's relationships with others would benefit.