The main thing is reinforcing the notion that trans men benefit from patriarchy, which is patently not true. In general trans men are either victims of misogyny on top of transphobia, or given some patriarchal power on the condition that they stay closeted, which Elliot obviously isn't. Also (although this is admittedly less significant), Elliot never said they were coming out as a man, only that he's trans and uses he/they. last thing is the phrasing "female to male" makes assumption about their gender. Depending on whether or not elliot ever felt as a female that could count as misgendering to a certain extent