I dunno, Blizz seems to realize that for all the backlash in forums and such, such things don't really translate that much into lost sales. If anything, they've got a big queer userbase out of the whole thing.
Blizzard did make a big deal out of it, they're been teasing a gay character since the game launched in the first place. They've made sure people were aware of it and even made another announcement not long before the reveal.
It's true that the reveal itself was done in a surprisingly low-key way, but Blizz made damn sure there was buzz beforehand.
They teased having an LGBT character but they didn't really make a huge deal about it. From what I know it was just a tweet answering someone's question or something like that.
