I’m pretty sure that if you re-pin it, it’ll get pinned for them again, and have to be dismissed again, but that’s one more reason that creating a new topic each month makes more sense. It’s at least as easy to create a topic as it is to edit one, and if you edit it, then how will someone know (without paying careful attention) that it’s been edited? Editing it and expecting people to notice, even if you pin it again, seems like asking for trouble. Creating a new topic each month seems like it solves all of your concerns.