Gossip has a terrible reputation, but most communities should encourage it. Gossip is the lubricant of many community interactions.
Gossip is how people exchange what they’ve heard and what they think about others.
Gossip creates a social punishment for deviant behaviour. Gossip establishes social norms, builds trust between gossipers, helps establish a social order.
Gossip encourages repeat visitors, it sucks newcomers in. It’s difficult to resist. Gossip provides insights not found elsewhere. It provides a constant stream of activity regardless of external factors.
Don’t ban gossip or off-topic conversation in your community. Make them prominent. Reference them in news posts. Do a round-up of the latest gossip if you like. Provide a unique place for it in the community.