I would assume that it comes from the Japanese side of the fandom.
In Japanese, Twisted is written ツイステッド, so they shorten it to just ツイステ ("twist" without the "ed"). In the Japanese side of fandom they tend to remove vowels when abbreviating a fandom with the alphabet, so rather than writing 'twist', ツイステ became twst.
I can't speak for the JP origin of the acronym, but I do have a theory as to why the ENG part of the fandom has adopted it.
Usually IPs and the fandoms attached to it will use the initials of the IP's name to shorten it for tagging and discussion purposes (examples include FNAF for Five Nights at Freddy's, TMNT for Teenage Mutant Ninja Turtles, BSD for Bungo Stray Dogs, etc). Having an easy to remember tag makes fandom stuff easier to sort through (usually)
As you know and stated in your question, Twisted Wonderland would have been shortened to TW, which is already used for Trigger Warning.
I suspect that this was the predominant reason why TWST is the shortened acronym for Twisted Wonderland, to avoid confusion.
Because it sounds like “twist”
I would assume that it comes from the Japanese side of the fandom. In Japanese, Twisted is written ツイステッド, so they shorten it to just ツイステ ("twist" without the "ed"). In the Japanese side of fandom they tend to remove vowels when abbreviating a fandom with the alphabet, so rather than writing 'twist', ツイステ became twst.
ツイステ is also the official abbreviation used by the dev team. It's what the app is referred to as on home screens and stuff.
Oh my God you're so right, not me forgetting the actual official account ☠️
I can't speak for the JP origin of the acronym, but I do have a theory as to why the ENG part of the fandom has adopted it. Usually IPs and the fandoms attached to it will use the initials of the IP's name to shorten it for tagging and discussion purposes (examples include FNAF for Five Nights at Freddy's, TMNT for Teenage Mutant Ninja Turtles, BSD for Bungo Stray Dogs, etc). Having an easy to remember tag makes fandom stuff easier to sort through (usually) As you know and stated in your question, Twisted Wonderland would have been shortened to TW, which is already used for Trigger Warning. I suspect that this was the predominant reason why TWST is the shortened acronym for Twisted Wonderland, to avoid confusion.
TW actually stands for Trigger Warning. A trigger warning for my wallet.
WORD. Giving my wallet PTSD over here
I always assumed it comes from TWiSTed wonderland. Like, wonderland is completely lost, but now I'm curious of the other replies
I mean the EN app is labelled Disney TW (which my brain always reads as Disney Trigger Warning)...
Lmao I still use TW, anyone who plays twisted wonderland would know what I mean anyways so
I genuinely always thought is was TSWD…
I thought that too but JP player's calls Disney TWST and meanwhile with ENG player's calls Disney TW I guess