Any events which would happen before June 20th would be a huge distraction from getting the game finished.
Not necessarily, they only need to send one or two people with a demo disc or a trailer on a flash drive. Beyond that they REALLY need some press coverage and they need to do something to not have their big release spoiled by all the noise and thunder that comes from E3 and the GOG conference. I would say it's absolutely vital they do something before June 20 because at the end of the day they need to make sure people know and remember this game exists so it doesn't hurt their sales and their future. Now is the time that has all the distractions for gamers with everyone wrapped up in hopes, speculation, anticipation and hype for everything related to gaming under the sun.