I see your point, but I still don't think the scene works, but thinking about it like that makes it much more watchable. My point is that the scene is simultaneously poignant and a throw-away. It's a "big deal" but also just one scene.

By the 32nd century, something like that should be such a non-issue for humans, that it would be like stating just another fact about yourself (amnesia and trust-issues aside), which lends itself to being a throw-away...but that defeats the purpose of the scene. Again, I am all about the message and Stamets' reaction, but it felt very 21st century and on-the-nose.

I'd have preferred if Adira were just non-binary from the beginning and maybe have a quick correction of someone when they were misgendered. Or, let that scene be the reveal of something else, like the symbiont. With that change (I'd have to rewatch the season to see where this scene was in relation to the symbiont reveal), I think the scene would still work while tightening up the writing. I also think it'd get the message across, too.

Now, if the writers really wanted that scene to stay as-is, there are options. Make them an alien from a culture not as enlightened (which would cause other issues) or have this scene play into a bigger theme of Earth backsliding post-Burn (like a Dark Ages) to have mores closer to the 21st century and show the 23rd century crew as horrified by it and work to bring Earth and humanity back toward enlightenment.

This kinda sums up my main problem with Disco. There were great options on the table to realize a concept, but they just wrote it in an awkward way that is unsatisfying (at least to me). Sometimes, that awkwardness reads as performative/lazily progressive.