When you look different and act different, you do not expect people to treat you any different. It is only normal that people would treat you differently. The reason , at least of the reasons why online casinos exist is to prevent or reduce harassment. I know that we have cyberbullies everywhere but using online casino is still the safest option for LGBTQ if they cannot stand the harassments.
Furthermore, the bodies in charge of land casinos should look into cases of harassment of LGBTQ people, help them get justice and pass a law that any casino where such harassment happens and they do not do anything about it, they will be shut down. This would make them serious in prevent such incident from happening.
We don't expect people to treat us differently but it's instinctive for them to treat us differently. Especially if we show it directly to them, they may immediately stay away from us because humans will instinctively protect themselves if they see something they don't expect. And online casinos make it easy for everyone, including LGBTQ people, to the harassment they can get when they play gambling in physical casinos.
Only the people around them know if someone including LGBTQ is gambling. But I don't think people will know as long as that person doesn't show it to the people around him. They will treat him the same as everyone else. But I don't know. This LGBTQ case has started to become a severe case in several countries because someone is going against their nature by behaving that is not by their gender.