I have a story I'm working on written in first person, and I never actually describe this character to be a male or female since I could easily see them as either. The name given is intentionally either gender. I am not necessarily aiming for the gender fluid angle, but I'm honestly okay if someone says that is what they get from it. Is the concept of allowing the reader to choose the gender themselves weird? Is it too subtle? Am I giving enough here for a decent conversation?
Lack of details quickly turn characters into props. Even things like giving a character a name add something to their development. Of course, anything can be done well, but I'm not sure readers are going to feel the satisfaction you're going for. I get that you're trying to be clever, but remember you're also trying to write a story. And ultimately you want the reader to form a connection with your character. The less readers know, the harder it is going to be to form that connection.
I feel like the pronouns will be an issue. If you use "they", that feels to me like you're making the character deliberately non-binary, which is fine, but doesn't quite sound like the exact effect you're looking for. And avoiding pronouns can get awkward pretty quickly...
I feel like this problem would be lessened in first person since most references to the character would be 'you' or 'I.'
It has and is being talked about. https://bookriot.com/2018/05/01/when-a-cis-writer-does-a-gender-reveal-correctly/
Sarah Caudwell’s Hilary Tamar series does this. Hilary has a personality, though it’s a fairly comic personality.
I believe by the name the readers will know your character can be both. I don't know what is in your story world but maybe your race doesn't see a problem with that? If this, of course, isn't in a fantasy world you have to be careful.
I'm not sure if I'm trying to be clever... I just haven't found the need to address sex or gender at all in the story. I don't know if I'm explaining myself well enough here. I guess I'll readdress the question when I post it for critique
If I read a book like that I think I would be weirded out. It sounds unique and interesting and I would like to see a book like that be pulled off but deep down inside I would start feeling like the character is less of a person and more of a "thing." I would probably keep asking myself "What is IT?!"
I like this idea, often if I'm imagining characters from their own POV it's not something I'm constantly thinking about anyway unless it's an important plot point. I think whether you would lose something by doing this would depend quite a lot on the story and the context other characters provide, like how people react to your character in different ways (e.g. some people in real life treat men and women as stereotypes so might react differently to your character accordingly). I do agree with the others that to be sustainable 1st person seems the easiest way to go. I heard about a fantasy series or novel where the author didn't ever mention if her characters were male or female but unfortunately I can't remember what it was called - I know I read an article about it though so there must be some people who agree!
Doing that for all her characters must have been exhausting. I only did it for the one in first person. I probably should have mentioned this is a short story, but I am thinking of fleshing it out if this idea isn't too weird or noticeable.
I could see a really well written story like this being something teachers would have students read and then discuss, and it would be an interesting discussion.