IMO it also has to do with the ever expanding list of "signs that you are actually trans." You have these young girls on tumblr and the fanfic websites fantasizing about their yaoi ships and getting horny. Instead of just masturbating to their "gay" characters without over analysing it, tumble tells them that picturing a dick while you rub your clit means that you have a phantom dick or whatever deranged thing other TIF fujos told them it is.
If you actively go looking for it, anyone could find plenty of evidence that they're "actually trans" since the criteria has widened so much it basically includes every normal human action.
Add to that the very same "totally not girls" that then try to gatekeep yaoi by saying cis women enjoying it means being an -ist and -phobic fetishist (like some other kiwis already mentioned), and you get even more girls basically pushed into trooning out.
Those Zoomers just don't get that yaoi has always been for women and that before the troon craze only the most naive would have ever thought those ships to be an actual, realistic depiction of a gay relationship. And now tumblr and Twitter are full of two girls larping as gay couples, it's truly wild.
This is not a defence of yaoi in any way, but the TIFs made something already weird much, much worse by actually trying to live a fantasy.
The discourse around it has gotten worse, as well. Mouse, AKA antis-delete-your-blogs, and LizCourseRants, are two of the biggest in this circle. From them, what would otherwise be young women masturbating to twinks fucking turned into queer rights and trans identity. I've seen far too many cases on how their Hannigram fanfiction is integral to free speech and now obese trans men need female care because fuck you, that's why. A bunch of them also supported Prostasia, which just got outed for employing an open pedophile. You love to see it.
It's one of the reasons I actually miss the 2010-2011 era of shipping. Yes, it was toxic, but the women knew it was just about dudes fucking, no politics behind it. Now it's ALL about politics and 'finding your true self'. And they love lecturing you about how their politics is right, vs being open ended about it as games like Deus Ex or MGS did. When you correct them, though, they get r
eal fucking mad.
When you're 500 lbs and can barely fit into your car, you have a problem. I bet bitches like her were raging over people not wearing a mask in public. And even with the fat, I can still tell she's female. So much for 'we just can't tell.'
Here is what happens when you google "Can men menstruate".
View attachment 4292075
Remember this nonsense is from the same people who LOVE to lecture the conservatives on "Not believing in science" while they deny biology 101.
I see this all the time on Jammidodger's videos when she makes them on BadWomensAnatomy or anything related to the 'evil straights' - obviously, the irony is lost on her. Sam Collins, another TIF, did this as well, mocking a conservative Christian pair of sisters on their 'backwards' belief on how only women menstruate. To make matters worse, they're doing this in state legislatures too. Guttmacher won't use the word 'woman', and neither will big YouTube doctors.
Menstruation is tied to sex, not gender - the thing they tell us not to confuse.
Speaking of bullshit claims, here are more comments from LonerBox's rape apologia video.

Just a simplification, bros, we just don't know.

We just can't tell! Lots of 'cis women' are clocked as males! They're more likely to be raped, so they need to be placed amongst those demure, peaceful women!

"You can't objectively define what a woman is. Sterile women aren't women, but I know transwomen are, because fuck you, that's why!"

Mouse there claims to be intersex and possesses both sets of genitalia. No word yet on what condition xe-xir actually has.