Why should sexual orientation, gender, sex etc. be of particular relevance in a zoo? As far as I know, homophobia / transphobia etc. is only relevant among human societies, not animals. As for the topic of animal sexuality, the zoo in question might establish a special exhibition on that, but I doubt that the majority of visitors would highly appreciate it. Especially not in conservative countries.Sexual orientation? (which I'd just like to argue is at least a little relevant in this context, without getting too deep into it)
As for ethnicity: this might mainly be an economic aspect to widen your visitor demographic. I remember a German zoo poll a couple of years ago asking Turkish and Arabian zoo visitors what they would like to have changed in a zoo to feel more welcome (large public BBQ places and special group ticket accounts for huge families were the most common answers). However, just as MRJ suggested, I guess cartering to one specific ethnic group might alienate all the others.