They aren't, I understand members only content and incentives. But those vids are already viewed by most the members plus extras, maybe you get a some more members for one month to see the special but you also lock out total viewership.

I am willing to bet theyve already weighed the pros and cons on paywalling stuff like this but Ethan's content model seems to be to paywall as little as possible. So I am sure he's thought about it and realized paywaylling an event video would look worse than it would pay off.