I find these threats doubtful, I don't see the editorial board wasting their life on sustained activism over the years chasing remnants of something they helped to create and what would be served a deathly blow by their resignation already. The author however has a history of activism I haven't looked into, but that usually involves a spin. There's also the possibility of his correspondents' misguided politeness by throwing him something to chew on to diffuse the blame. Mathematical Intelligencer editor could be seen as doing that in a somewhat more intelligent way blaming the possibility of "international hype".

As for the description of alleged emotional states involved, I'm oblivious and not seeing the relevance. Recounting the events and actions taken sufficed for a horrific story. The author deemed it important however to make it into something even more colourful with threats of some unspecified future actions (how does one harass a journal?).

The managing editor you speak of went on leave and has an interim replacement. I can see that entirely appropriate if only because of how retraction was handled by deletion and overwriting, instead of a proper notice in place. This was extremely unprofessional administration, which is usually a duty of the managing editor solely. The other possibility I described is that it wasn't really published the usual way, which is even more damning.