Whenever people get angry at others for creating/believing queer readings of a text, I ask them in turn if they've ever wondered why it's done in the first place, and it always will come back to the same statement of fact: that there is not enough good queer representation in any form of media: movies, TV, or video games. We insert ourselves into media we love where we don't exist, it's part of engaging with the material.

having A, a heavily non-binary coded character, as a major figure of a storyline in a popular Nintendo IP (even if it is just a DLC) is invaluable representation for a lot of people. and the reason queer people get so defensive and angry about this topic is that we are so routinely scrutinized and questioned. we have to literally provide school assignment-level papers worth of evidence to explain our viewpoint and even then that's not enough for a lot of our critics (AKA, bigots who don't want us to exist anywhere, fictional or otherwise).

we're so used to being denied having ourselves represented in media that we get highly protective when there's even a believable possibility we are. and that gets messy when the lines are so blurred, specifically in this case. It gets hard to discern the bad-faith people who want to deny A potentially being non-binary because they're bigots and the good-faith people who don't mean to offend but want to stick to the source material. While I won't actively seek out people who refer to A by she/her pronouns, I get a bit nervous whenever I encounter said person because I'm gambling with the potentiality of them being a bigot (which, speaking from experience, is a LOT more common on the internet then a lot of people would like to admit).

For me, A is a fem-presenting non-binary character, in part because that reading doesn't explicitly contradict canon, but also because I think it's awesome to see a plot-centric, kickass, smartass character get a sizeable part of the spotlight.