I am not sure whether OP meant they specifically DIDN'T want the parents to come, or if they just were more directed at the kids?
I know plenty of totally legit churches who invest a lot of time/energy/money into kids programs, put up fliers, and encourage the kids in the church to invite their friends, because it is a good way to attract families to the church - nothing necessarily skeevy about that. I also know families who will send their kids to Vacation Bible School or Sunday school and not go themselves, for whatever reason.
However, the way they are going about this (legit or not) is really inappropriate to the point of foolishness, and even if they are legit and trying (badly) to do something nice, it is having the exact opposite effect. Very off-putting and creepy.