That is unbelievably sloppy on Twitter's part. Not acceptable at a tiny company. I would fire everyone involved with posting the credentials if that's true.
That said, I'm not convinced this story is true but it does add up.
The only thing we trust twitter to do is to provide some notion of authentication for well known users. That's still very important and not something Twitter can afford to lose, but it's not trusting them "with our data", I feel that is a very heavily overused phrase these days.
If these hackers had been more subtle and somehow made the confusion last a long time, it could have been a lot more serious. If people can't rely on Trump being Trump and Musk being Musk on Twitter, then Twitter is just an overgrown internet forum.
Thats our data.
Do they? As far as I can tell, Twitter is for loudly shouting all your ill-conceived thoughts in public.
Don't post anything on twitter you wouldn't stand on a street corner screaming.