The suit claims:
13. For consultants, developers, and producers of RPG games to succeed in that industry, they must attend Gen Con.
Is this an absolute truth? It seems to be a pillar that the case is built upon, and if shown to be false, the case could likely suffer a little. Not that this changes most the arguments of defamation.
As a former small publisher and working with others I can say that GenCon was up till I was no longer able to attend, and according to others, up till fairly recently at least... still one of the bit cons to go to to tout your game or yourself. That and Origins till that con started acting weird. Cons in general are a great place to do alot of things you cant normally, or at least easily, as a publisher, designer, etc. And one big one, up till the plague, being meeting people face to face and pitching whatever.
I would though say Zak is putting too much emphasis on being able to attend GenCon as vital. Especially with the current plague situation putting a damper on cons, or ending them totally in many areas.
I'd more say GenCon is the biggest and most important of the gaming cons and being banned from it denies access to those resources.
If WOTC also tried to leverage banning him from say Origins then he'd really have some ammo against them. And he should be keeping an eye on other cons to see if they have been trying to do exactly that.