Enerhpozyks

It’s not whatever the society say : trans only have sense if you have a gendered society. That’s what “social construct” means, this is also why it don’t apply to all cultures.

A fluid identity might not be “trans” in a society when there is no question of gender, but you won’t call that being “genderfluid”, as having a “locked” gender may seems weird to them. Maybe they won’t even have a word for it. But it’s still won’t be cis, either.

And elven culture here is binary gendered, hence the changes Corellon do.

I see what you try to do, but again : gender has nothing to do with your genitals/body.
Gender is a social construct and thus, it’s difficult to say “always”, that’s why there was terms like AMAB/AFAB in the first place : you are not born with a gender, you have been assigned with one to begin with. Hence the change. Trans is not just about your body, but also about how everyone and the society percieve you (that’s why you have multiple type of coming out).
And fluidity is a constant change, not a gender. There is nothing cisgender about changing gender, by definition.

Nope, cis mean you did not changed your gender, it has nothing to do with your genitals. Corellon change gender quite a lot.

Genderfluid is not cis, therefore trans.