I am a local. In fact, I can watch MK fireworks from my house. But I still enjoy the full vacation experience and just happened to have a trip already planned that lined up perfectly with the preview dates. I made the reservation in January, direct with Disney. So they won't get extra money from me that they wouldn't already have received anyway. I am sure there was some method to the email madness - just not sure what. I haven't seen a common denominator for either those that got the emails or those who didn't.
For the record, I have a Florida Res Platinum pass, but my sister and her husband got the emails and they have Florida Res Silver passes (I think they are still called Silver - it's the one with all the blackout dates). They didn't try to book it as they aren't able to come over that week.