If you put to one side those folk who have gender dysphoria, the issue has risen these last few years because the gay movement made a political decision to embrace gender ideology, there are reasons why they bolted this incongruous, dangerous bullshit to their cause, but bolt it they did.
Put simply the mantra is we're all born with a gender identity, you, me, everyone, our sex is no longer observed at birth but assigned, our true gender begins to emerge from a young as two. According to this madness there are signs like a preference for dolls in boys and action men in girls. Once these gender indicators are observed your sex becomes immaterial, gender is all and like the cult they are, they demand the child must be instantly affirmed! And the long road is then set out for them, a rocky road that may well involve major surgery, the loss of the ability to orgasm and lifelong hormone treatment, not to mention loss of cognitive ability and possible osteoporosis brought on by puberty blockers.
The reason that trans women are so often at the forefront of this, hence the post you referenced, is that being men they alpha male the shit out of it, they're the drivers. We're already seeing trolling and accusations of hate in here from allies of the cult and it gets worse if you actually counter their bullshit with facts.