Sprite - time will tell, but at least one of those members instantly made a new account. She "quit" because didn't want her private information from her old posts to be a target for hackers, so she was dodging them.
In the past we've had several situations where someone didn't like forum policy, they made a long post and quit, and then a month or two later they were back with a fresh account. It was a form of "drawing attention to their beliefs" more than a permanent decision. Again, time will tell.