I think there's a much simpler and less juicy angle here: someone posted a screenshot of an internal communication, and it got removed. It's not surprising or controversial that Twitter would try to contain a leak of its own internal comms (a screenshot of their slack). This isn't "Twitter took down a disparaging post about Twitter", it's that they tried to stop the sharing of internal data.
That being said, I don't disagree with the sentiment here in the sibling comments, this just isn't the steelman you're looking for.
Best of luck to all remaining and recently parted Twitter folk.