When I last looked at Slack, they let the free plan access the last 20000 or so messages, which means the small private instances won't have to pay for years, a

When I last looked at Slack, they let the free plan access the last 20000 or so messages, which means the small private instances won't have to pay for years, and by the time they reach the limit, the information is stale that perhaps no one will miss it. For those small private instance, there might not be many messages left after the 90+ days are hidden.