Or maybe it's for an AI roleplay bot

That did occur to me, but the phrasing of "future girlfriend" seemed a little off for that in the context of someone accepting and understanding. It would have the same vibes as when I hear boomers who are trying to be accepting but are just a little outdated when they say things like "back when [person] used to be a boy". Which it is my understanding is not generally the preferred way of speaking about it.

But I'm neither trans no currently close friends with anyone who is, so I'd love to be corrected if I'm wrong.

So yeah, I was thinking mainly the AI thing, which doesn't seem super healthy.