The discussions on that Group became outstandingly ridiculous.
I didn't follow it all in detail, but there seemed to be a few sane voices (including some people from here) who said don't do it. Some people who lived closer than most also said that, and that it would likely antagonise the locals and potentially disrupt the rides future.
They were also quite a few, albeit probably a vocal minority, who were in the "why shouldn't I do it, it's not breaking any rules" category, and presumably thought that they were the first ones to think of cycling it independently this year.
If it's a nice warm night, as has happened on some previous occasions, there will still be a significant number of people attempting it. The car park will fill, the roads will get busy, and people will try and use the toilets and cafe. Regardless of all the "my boy/girlfriend will pick me" up statements, a fraction will still try and use the train to return.
On most 'normal' years, I suspect this causes a certain amount of annoyance, but this year it will
really annoy those who live locally, and cannot avoid it all. This is probably not a good time in the world, to be doing that.
I guess it rapidly degenerated into a "I want to do it", "Don't do it" ... repeated ad nauseum. I saw several new posts appearing, suggesting how it was OK, and legal (possibly) and sensible (less likely to be true). Followed by a series of contrary arguing posts.
It wasn't useful, or helpful, so I can see why the Group was closed (hopefully just temporarily).
The Dunwich Dynamo is typically enjoyed by a lot of people, and has probably encouraged a lot of people to cycle further and get more exercise, over the years. It's a fun social event, and demonstrates that cycling can sometimes be more than just getting from A to B (which is also useful, but in a different category). Some people no longer seemed to be treating it like that, but as a challenge to the "powers that be", and finger up to authority. That's sad.