You’ve already gotten some pretty solid answers, but I wanted to chime in and reply to your post as well. 
I think representation of the LGBTQ+ (and mintorities in general.) is important not only in WoW, but media as well in order to share and tell the stories from the perspective of said group.
Media representation matters because we live in a society where factors like gender, ethnicity, sexual orientation, etc influence our lives and the experiences we have, and the issues that affect us. If the same people are producing and representing roles in video games for example, only certain stories from the perspective of majority groups get told. When the minority and less privileged group is depicted by the majority, it tends to be in a very stereotypical and narrow manner.
An example of this is often how LGBTQ+ is represented, more specifically gay men. They are stereotyped to be very feminine, flamboyant, promiscious, dramatic and over the top. In reality however, that’s not always the case. It’s important that it’s represented in such a way to show that the LGBTQ+ isn’t the stereotype that many of us have grown up to hear about.
If I were to have children, I don’t want the only characters they look up to to possess none of their physical qualities. Just as poor media representation has the power to instill negative prejudices and stereotypes about groups we don’t identify with, especially with youth.
Also, not to mention that representation is a sign of society moving forward, and that stories from minorities are not only being told, but actually heard. Sometimes this is for the better, sometimes the worse (As we’ve seen on the forums lately) But they are being heard.