Would such a club would work now, and is there a need for it?

If there are enough like minded people in an area, there would be a need and it would work.

Every club and session I've been to a few times has had some form of "rules". OK they may be unwritten but there is always some sort idea as to what is appropriate for the occasion.

I'd say that sort of rule/understanding would include "anything goes" but I don't think I've been to anything that really is. It usually seems to extend things into the pop/"acoustic" type direction but I can't imagine many being too happy if "anything goes" was interpreted as welcoming operatic arias.

Whatever. I don't see any point in arguing over how someone else's club or session runs. As far as I'm concerned, someone could set up an event with no instruments or no singing rules, another, traditional only, another "anything goes" and others somewhere in between, and I'm happy.

As a listener and participant, I simply pick the events that suit me best in my area. My first priority is an Irish instrumental session but I can also enjoy some rather broader events.

From a purely selfish perspective, I would loose out if everything became specialised/rigid and if everything had to cater for all interests.

My wider view is that I feel that the broader folk scene is healthier with a diversity of events each running its own way that it would be with one right way for all clubs imposed.