That doesn't mean their claims are false. But you should always be skeptical.
The second issue is the trial resulting from Elon Musk walking away from the Twitter acquisition. That acquisition agreement calls for "specific performance", which means Elon pretty much agreed to buy the company no matter what (he waived due diligence). He is expected to have to pay a fortune if not actually buy the company in his trial next month.
So it's at least worth noting that this disclosure happens right at a time when it might help Elon. Maybe unrelated but it's also a hell of a coincidence.
Employees that are fired (or are heading in that direction) can make all sorts of claims to deflect away from the fact that they were or soon would be fired, possibly with cause, possibly not.
The specific claims seem to be a little vauge like not giving employees tools to combat bots. Like what does that even mean? Twitter may have crappy infra for this but does it rise to the level of negligence or even malfeasance? That's not a slam dunk from what I've seen.
Keep an open mind but remain skeptical.