I can see how the person/people who put up the flyers thought perhaps it was a good idea--to me it's the classic case of only discussing something with, say, your like-minded spouse before doing it, and not running it by anyone else. For some reason I picture a couple as being behind it.
One keeps complaining, and the other goes into fix-it mode and comes up with this idea, and they both think it's brilliant.
But very poor execution. Logistically bad, extra work for everyone, going to be a mess on Halloween with the obvious A-list/B-list. If at Halloween one's neighborhood is being flooded with large numbers of poorly-behaved, poorly-supervised children whom you suspect are from other areas, I think there are far better ways to deal with it than this--something neighborhood-wide, perhaps, like proposing ToT at the local mall or rented space instead of house-to-house, or asking for greater police presence in the area that evening. A municipal solution for a municipal problem, rather than one couple trying to make an exclusive candy club in their house. They could even, as others suggested, host a Halloween party with invited guests from their neighborhood, and then not give out candy at the door at all.
I lived in a rural area near a very small town, and ToTing was kind of foreign to me anyway. I would dress in a costume, and my dad would take me only to the homes of people he knew--the idea of going to door-to-door when you didn't know who lived there seems odd to me, and this was 25 years ago in a town of less than 5000 people, so likely to be quite safe. We would only go to maybe five or six houses, but people tended to be generous with the candy, so I always got a big enough haul that my mom would take it away and limit my sugar intake. Maybe that was their plan all along!