Hadn't finished the chapter yet when you posted this, but by now I have and now I can comment on this. Really liked this one. Again a chapter full of vivid descriptions, and that twist was despite the speed at which it came, well earned.
I've seen this style of hinting at the character's inner identity in other books too and it's a trope I absolutely love. It allows the writer to write outward actions, even thoughts, matching one mindset, and yet hint simply with the name, that their subconscious has a different idea. You feel brilliant when you catch it emerging.
In some works, there are also phases when the author uses a "fakish" name e.g. a more formal name for a character, but in one moment, the "real" name comes back and you know, boom!, a transformation happened and now things are gonna get real!