If your community organization uses FB as its primary interface, you don't actually have a community organization; you just have a club for you and your friends...
Currently trying to get myself added to the local FloodWatch group. It only operates via Facebook and WhatsApp. The only way to get on the WhatsApp group is to post a message on the Facebook page. OK I have a mostly dormant account just for this kind of thing, but Facebook keeps automatically deleting my post for breaking some arbitrary rule I don't know. Please, people running local emergency response networks, don't have it operating in walled gardens where people can't easily access the info