This is exactly my view. Is there a "demand" for this? Absolutely not because unless you have the creativity of a rock you can D-I-Y this sort of thing and I'm sure it has already been done dozens of times over the years. Just people seeking attention that have a difficult time expressing themselves without looking like a runaway train. Nobody cares how you run your setting, just run the game that you want to, it affects nobody outside of your table unless you make a spectacle of yourself. Just play the game with the parameters that everyone at the table is comfortable with in an environment where everyone can have fun.
In the science fantasy campaign I used to be a part of, I played a character that was of the succubus/incubus archetype. And she had her own view on sexuality. Which was quite fluid. Being a shapechanger, she could be any gender she wanted. Or none at all. And she was married to another of the same species. Who also preferred a female form as her default.
When playing this character, I looked at what she brought to the game. Which was a considerable skill set. She was completely the expert in her fields. And relied upon by the rest of the group because of it.
I admit I downplayed her sexual aspects for the most part. Only bringing them out when they added a little color and fun to the game. I didn't want to overdo it. Didn't want it just done for a cheap thrill. Because the character had far more mental and emotional depth to it than what people saw on the surface.
But my point is? This can be done in any game with a broad enough ruleset and character options. You don't need a special branded game to do any of this. Just an imagination and good player skills.
The game that is the subject of this thread doesn't bring anything special to the table that couldn't be already done with existing games. All it's doing is to exploit controversy to generate sales. Which honestly? I'd rather someone show me what makes a game product special. Rather than hype.