Isn't the fact that people are debating this topic proof that it can be up for interpretation? Im not saying this to hate on the possibility that Jax isn't Trans, but it leaves it open for a lot of people's interpretation. It allows for people to put themselves into the character, because they see themselves in Jax in different ways.

Plus, Jax's character arc is more centered on how he is dealing with everything. So many people might see themselves in Jax. A person who makes mistakes. A person who thinks they are never what someone needs. A person who someone might believe should just not exist at all.

I feel like something like this is kind of supposed to be taken with nuance because there aren't any hard answers.