Yes, the state of the cymbal is info that should be available to the buyer, of course.
But, I think the debate is more about what makes a cymbal considered as new/demo/used.
In my opinion, a cymbal is an instrument that needs to be tested before purchase, whenever possible. Testing a product doesn't necessarily make it a demo piece.
I wouldn't be comfortable ordering a new Sweet ride without the chance to hear it first. I would want to audition as many as possible before making a decision, because I know they have good ones and not so good ones.
I don't think my testing out a cymbal for two minutes would anyhow lessen the value of it, or bring it down to the demo cymbal -price category.
Then you might have a cymbal that has been brought on display at NAMM, for instance, where everyone will have a go on it just because they can. That would be considered a demo cymbal in my opinion.
And then you have used, as in a cymbal that has been bought and owned by someone and is being resold. Doesn't matter if the buyer ever played it or not, it can still be "like new", but it is still used.