HR-level discussions should be documented at all times, so that seems like a poor example to use here. I truly feel that if the chat platform is being provided

HR-level discussions should be documented at all times, so that seems like a poor example to use here. I truly feel that if the chat platform is being provided by the employer, then they have every right to disallow you from taking conversations offline. The problem really lies with Atlassian for not offering better permissions.