I've been around the scene for many years and it kinda just morphs from one trend into the other, each equally ridiculous. Before there was a big hypno trend and gooning/hormones emphasis, there were the captions. It still exists, but only in attenuated form really. Half the captions you see in kik groups and on Twitter actually still come from old Tumblr blogs before the purge lol.
But in essence, the stupid bollocks back then was in the caption content stuff like "she told you to wear her panties and now you're a girl getting fucked by her male friends" etc etc, and people would share it accompanied by their own text to say "this is exactly what happened to me". Almost always fake attempt to project a desire into reality and become this fantasy through an avatar. Took a whole batshit twist when "bnwo" became a thing too. Then I saw people doing it with chastity play "I caged up and now my dick is half the size" (no it's not, it doesn't shrink meaningfully at all - alas). And then with hypno, "I listened once and then I turned into a cock sucking sissy fa**ot" etc.
There's basically always been a channel for absurd fantasism in the sissy kink world, which changes as the technological means to express it does. When that's big enough to encompass a scene/subculture, it then becomes the cover for people who might well have transitioned anyway but now do it under the cover of a kink or it captures in its net, sadly, genuinely unwell people who have an array of problems (including psychotic/delusional people – have sadly seen this in my time too).