Alright it’s 8am and i have an 8 hour shift ahead of me but I’ve been really mad about this trope for a while so I’m gonna answer this now. First of all, thank you for actually taking the time to ask this question! I appreciate that, and clearly you’re a good egg.
However, the whole concept of gender bending a gay man is bad.
Do we have a fandom here based on a Victorian novel with very few women? Absolutely. Are a lot of fandoms, even modern, lacking in women? Unfortunately yes (I really will never understand that but that’s a story for a different post). But is it ok to get your female representation, queer or straight, by taking away gay male representation? Absolutely not.
I think that being on the internet, especially in queer friendly places like tumblr, often makes people forget how little representation queer men actually get. Occasionally one side character on a major TV show is a gay guy, but that’s pretty much it. We don’t get to see ourselves reflected in the media we consume pretty much ever. We are, in fact–gasp–a minority. And as I’m sure you know, that really fucking sucks.
So when you look at a fandom, see the only gay man in it, and go “I’m going to create representation by taking this character away from another minority,” you’re doing a shitty thing. When you make a gay man (like Enjolras) a lesbian, rather than taking a straight coded female (like Cosette) and building a badass bisexual character for your headcanons, or taking a random guy (like Jehan) and making him nonbinary/a trans woman/what have you to bring more gender and queer diversity into the fandom, you are basically saying “I don’t care that this is an important piece of representation for gay men that was explicitly included by the author; you are not enough of a minority for your representation to be important, so I am taking it now.”
Rather than stealing from each other, we need to be adding to canon with our headcanons. So perhaps next time you get frustrated with the number of women in a fandom–which is perfectly justified–carve out your representation where it won’t harm gay men.