Currently the Settings app in windows doesn’t have the same level of features as the control panel does. It’s definitely got most features that normal users will need, but if you’re a power user or a system admin, you’ll quickly find yourself having to swap over to control panel to configure anything past the very basics for quite a few different parts of windows. This change will be fine if Microsoft achieve feature parity between settings and control panel, so that there’s no lost functionality when they get rid of control panel.
I think most people are a bit upset at the idea of the control panel disappearing because they don’t trust that Microsoft will end up reaching that feature parity, leaving people with less options to control their own devices effectively.
I think posters/flyers are one of the most powerful ways to reach people in a local area, you’ve got to be in the local area to see them, right?
Another way to spread the word can be via the internet, Facebook is god awful, but a lot of communities will have something akin to a noticeboard that is another effective way to get the word out.