Do you have a source for this claim?
Yes. You are welcome to ask the other people who helped organize the previous EAGs about it. If you like I can try to work out the dates.
Also, I would note that if you allow unsourced positive claims, but not negative claims, this isolated demand for rigor creates a bias and make us vulnerable to hostile actors whose behavior cannot be called out. Though of course you can moderate your forum however you like!
I think Gregory_Lewis is referencing the same poor behavior here if you are looking for more sources. Please let me know what the organizers say if you ended up asking them.