I get that the series is aimed for kids and it might be a personal thing for me, but it feels as though it's going to be shoehorned in to be woke instead of making sense in-universe. Keep in mind that the world is essentially in the middle ages during the events of the books. The Scorching almost rendered humanity extinct. Thousands of years later, Stone killed Queen Oasis and caused the majority of their villages to be targeted and burned down by dragons for around 20 years in search for the Sandwing treasure. It's explicitly stated that the humans are endangered and the dragons didn't take them seriously, seeing them as non-sentient pests/pets/prey prior to The Dangerous Gift. Basically, unless you get exceptionally lucky like Stone did, you're not slaying any dragon, end of discussion.
In Dragonslayer, there were pretty strict rules in Tailsman about attracting the attention of dragons or insulting the dragonmancers. In Valor, nobody was allowed to basically piss off Heath or go outside if you're not a Wingwatcher and any rulebreakers were outright banished for it, or for any reason if Heath felt like it. The Indestructible City is the only settlement that fights back against dragons, every other place involves hiding until they go away.
Why am I bringing this up? Because humanity's focus is on survival, first and foremost. Praying that the dragons don't make them their next meal. Nobody in-universe is against that, not even misanthrope Wren. So I believe it's a certainty that if a human tried to be transgender or non-binary in their universe, he/she would get laughed off and told to do something more important. I think even Ivy would've told them to focus on making peace with the dragons or something.
We don't know the history of the humans on Pantala, but I imagine that they're focused on survival just the same.