Situations like this really illustrate the key issue facing meaningful trans discussions today. Far too much focus is put on the physicality of being trans when the genuine defining trait of trans individuals, especially those who undergo transition, isn't physical it's mental. Being 'trans' by DEFINITION means that at some point you were considered cis by everyone else around you. How long you were considered cis really varies by individual, but for all we know the actor playing this role could come out as trans next year and it would, in fact, be a trans woman playing the role. There's no real way to tell at this point in science.
Speaking from my own experiences as a trans person, as well as being friends with and dealing with many trans people of varying degrees, it has been made apparent time and time again that being trans isn't about dressing, presentation, or 'passing'. It's about being so completely disenfranchised from your existence that you must rearrange your physiological furniture to make it the slightest bit livable.
Being trans is like being dumped into a house where someone else committed a grizzly murder, the blood is still all over the walls, there's a rotting body in the corner, and the furniture is all upturned. You do your best to live with it because everyone else thinks the house looks fine from the outside and they all think you must be nuts for wanting to move out. Of course in this metaphor 'moving out' means killing yourself, but most would rather not do that. So what do you do instead? You bury the rotting corpse in the basement, scrub the blood out as best you can and rearrange the furniture so it's as comfortable as it can possibly be. You'll never get all the blood out, the basement may be a little haunted, but you've made it the best home you can to live out your life. Using this metaphor dressing, presentation and 'passing' are all extremely superficial, like changing the curtains or buying a new sofa set. They're things you do to help make the home cozier still, but they're not the reason you have trouble sleeping at night and hear creepy sounds coming from the basement.
Being trans is ultimately about the disenfranchisement of self. The loss of identity to such a degree that you do not exist in the world while still having to endure all of its suffering. Dressing, 'passing', etc, are desperate attempts to reclaim that sense of self, a fervent bid to show people who you are and be accepted by them. To use the above metaphor, it's like inviting them into your house and hoping that the ghost in the basement doesn't scare them away. Movies about trans people should focus more on that internal struggle, the fight to reclaim a sense of self, and less on how hot the protagonist looks in an evening gown. They shouldn't revolve around 'passing', they should revolve around acceptance.
Being trans is about how you handle the internal struggle, not what you look like or how you're endowed.