As per IUP's Microsoft Teams support page, MS Teams spaces are subject to deletion after at least one year of inactivity. This would include the entire team space, including member posts (which are referred to as "channel messages" in some reference materials), files, channels, etc.
In addition, a 90-day retention for person-to-person chat messages (those not affiliated with a Team) in IUP's Microsoft Teams environment will be in effect beginning the week of September 28, 2020. All messages older than 90 days will be deleted and a rolling 90-day retention schedule will be established.
IUP's MS Teams environment is governed by IUP's Acceptable Use of Information Technology Resources Policy. Chat messages are only to be used for transitory record purposes and should not include sensitive data. Chat message content is subject to litigation, investigative hold, or other lawful requests.