@Baileyonice, do you speak any other languages? In most, gender runs through absolutely everything. It's not a case of a quick 'trans' and 'they'.
Bianca Barreto's case wasn't about pronouns; she was convicted of saying the politician is a man because he's male.
She went on to say people try to impose things on us that are not real, that are a product of her imagination. By ‘her’ I mean the person, because a man is a man, a woman is a woman.
This is a handy illustration of the way gender gets lost in translation. Portuguese for 'the person' is 'a pessoa' - a feminine noun, which takes feminine agreement. There's no getting round it. You can't evade the issue by pluralising it, as your 'they' would also be gendered. The noun for 'people' is also feminine ('a gente').
Third-person pronouns aren't only for talking about someone, as in English. In formally addressing someone by their title, Portuguese uses the third person directly. So a waiter would ask: A senhora gostaria de gelo? 'Would the lady like ice?' This simply does not lend itself to a 'trans' prefix, it'd be like yelling that the lady is transgender. And linguistically wrong - Brazil, like many other countries, has a language authority.
Moreover, all further address must use the matching third-person pronoun. You'd end up sounding like 'Would the trans-lady like ice, or shall I bring trans-her something else?'
English speakers make a lot of assumptions about pronouns being trivial, titles being disposable and linguistic flexibility. Our own language was as observant as others until around a century ago, though mainstream English has never had comprehensive gender. Now it's a bit of a free-for-all, we easily forget that most other languages have gender baked into everything, most use formalities that we abandoned long ago, and many value linguistic integrity so highly that their governments protect it.
Way back when, this forum saw long discussions about whether this makes it easier for English-speakers to dismiss 'trans' language issues. There's also a significant concern that gendered languages make it incredibly hard to separate 'acquired gender' from reality, since reality must be described using fixed genders.
Your reply prompted me to make this additional observation. Someone else might choose to start a fresh thread on languages and genderisation?