If Aiello announces The Purge by saying something like "The Purge: Anarchy will be one of the many scarezones for the event this year", There's a high chance people will understand that there will be more. I'm sure he's not gonna be straight forward and say "The Purge is gonna be on the streets". He always makes his point clear. I don't understand where you heard that the GP think TWD is all streets this year. If they think that, then they haven't watched Aiello's video, which doesn't make sense to me because the video is RIGHT THERE as soon as you enter the website. Anyways, back to my prediction... I expect The Purge to be the next announcement, due to "marketing", for the movie, which comes out in a little over a week. Maybe they'll announce it the day that it hits theaters? Who knows. Not sure about you guys, but I see it as a smart move, and if they end up announcing it, I'm satisfied for the rest of the month.
(And I'm pretty sure the GP doesn't start going on the HHN website until it gets closer to Halloween time and they are thinking about going because they saw an ad on TV or somewhere on the internet)