Because they don't think of it as roleplay in the banal sense - in an age where if you're without a social media presence, you're seen as a nobody, the avatars people have are intended to project one's idealized self. This is why digital art is a currency online, as many trans people have animal or outlandish but still recognizably anthropomorphic profile pictures and avatars, usually with desirable sexual characteristics - given they have already untethered themselves to their physical, real-world appearance and identity already, it feels necessary to embody an idealized one online. This translates into the logic implied in that Tweet that male interests are uniformly gender-confirmative and any interest in female 'aesthetics' must be evidence of transgenderism.
You can see the inverse version of this thinking in mainstream consoomer Hollywood, particularly from Disney - characters are increasingly written in anticipation of the belief that people outside of that character's demographic cannot relate to them in any way.
I personally often default to roleplaying seductive, villainous and/or authoritarian female characters because I'm a fan of that trope on TV and in movies, not because I'm convinced it's representative of my true self.
Did she specify 'white working class'? Because I imagine the patriarchy, in this context, would be men of all stratas who would have been #metooed 6 years ago but are now practically encouraged to supplant, humiliate and speak for women.