I get the concept of the "con exclusive trailer". It creates hype, gets you the headline slot, builds an audience. But it's also frustrating.
DC's Suicide Squad and Batman vs. Superman trailers created an explosion of media coverage and fan excitement. A rapid YouTube release caused a second wave of anticipation from a primed international audience. Exclusive = exciting.
Deadpool equally garnered critical/fan acclaim, but that hype train is exclusive. Can't afford to go to San Diego? Wait three weeks. I will (begrudgingly), but I'm already a fan. Any potential new audience was just abandoned, left asking "Dead who?". Exclusive = forgotten.