My mother tongue has no gendered pronouns. When speaking English, I regularly misgender eeveryone, because my mind cannot really wrap itself around the concept of having to keep track of my conversation partner's gender. Or that of someone else. Even people I've known for decades have an about 5% chance of being misgendered.
It feels good that I can ignore people's gender and just talk about a human. This might be an incredibly alien concept to an Indo-European, though. But still, people who only started learning Indo-European languages such as English, Spanish, Ukrainian, German, Albanian or Greek, at the age of ten will not have learned the concept of gendering people in time for it to not feel glued-on-top.
When I'm talking about everyone else as they, that being a way to avoid thinking about people's genders, it feels odd to then speak differently about transgender people.
At least I don't want to be only a gender. It's much better if people can see the actual individual behind, and trying to find ways to forget about the concept of gender helps glue less stereotypes over my image as it stands in someone's mind.
The gendered pronouns in Indo-European cultures are a very sad and harmful phenomenon. I'd say it's the better the more people stop their usage. A man (and that also includes trans men) is a man even if you don't spend every moment keeping track of their gender when talking. "They" helps see the individual.
Plus, it means not imposing another culture upon us who don't have gendered pronouns.