2 major issues. One being the already commented on limitation that you cannot set a policy for less than 30 days. Another, and even larger issue, which I only find mention here: https://urldefense.proofpoint.com/v2/url?u=https-3A__docs.microsoft.com_en-2Dus_microsoftteams_retention-2Dpolicies-2Dfaq&d=DwMGaQ&c=1BXtvEoDZ8OoKVrbcaT-lQ&r=qicaA1ovBXCm8Njd06V_SDVuuC3_CleUzqCfATT-WQ4&m=urrPL1N2VLh_EzKrWw2gY3YxhdPY9ctc1_MFA2hDgjI&s=sBsJDe9irRazdXPW0C7tCW2sE9-trdsXZPQdzcIHb-s&e=
Can we include Teams in org-wide policies?
No, not currently. You must create specific policies for Teams chat and channel messages using the Teams location row or these Teams cmdlets: https://docs.microsoft.com/powershell/module/exchange/policy-and-compliance-retention/new-teamsretentioncompliancepolicy?view=exchange-ps & https://docs.microsoft.com/powershell/module/exchange/policy-and-compliance-retention/new-teamsretentioncompliancerule?view=exchange-ps. These cmdlets have get and set versions as well.
So, you cannot create a default org-wide policy and have it actually do anything. I have created one for our organization, waited the 30 days, and then some, no deletion... This is a BIG issue for something that is OOTB supposed to allow users to just create Groups/Teams on the fly as often as they want. If you are not in control of groups being created, and you cannot manage them on an organization-wide level, what good is this option to setup a policy?
This detail was only brought to light after opening a ticket with Microsoft Support who directed me to the following articles to "make sure the policy is configured correctly."
https://urldefense.proofpoint.com/v2/url?u=https-3A__docs.microsoft.com_en-2Dus_microsoftteams_retention-2Dpolicies&d=DwMGaQ&c=1BXtvEoDZ8OoKVrbcaT-lQ&r=qicaA1ovBXCm8Njd06V_SDVuuC3_CleUzqCfATT-WQ4&m=urrPL1N2VLh_EzKrWw2gY3YxhdPY9ctc1_MFA2hDgjI&s=wz77Db8rp7JxpzmsFk2yuQhegteR6WabzblmsL-Me_k&e=
https://urldefense.proofpoint.com/v2/url?u=https-3A__docs.microsoft.com_en-2Dus_microsoftteams_retention-2Dpolicies-2Dfaq&d=DwMGaQ&c=1BXtvEoDZ8OoKVrbcaT-lQ&r=qicaA1ovBXCm8Njd06V_SDVuuC3_CleUzqCfATT-WQ4&m=urrPL1N2VLh_EzKrWw2gY3YxhdPY9ctc1_MFA2hDgjI&s=sBsJDe9irRazdXPW0C7tCW2sE9-trdsXZPQdzcIHb-s&e=
https://urldefense.proofpoint.com/v2/url?u=https-3A__techcommunity.microsoft.com_t5_Microsoft-2DTeams-2DBlog_Retention-2Dpolicies-2Dfor-2DMicrosoft-2DTeams_ba-2Dp_178011&d=DwMGaQ&c=1BXtvEoDZ8OoKVrbcaT-lQ&r=qicaA1ovBXCm8Njd06V_SDVuuC3_CleUzqCfATT-WQ4&m=urrPL1N2VLh_EzKrWw2gY3YxhdPY9ctc1_MFA2hDgjI&s=y7QiI0KVnhrcU7c8h_L9PCo7iArXhXMukOs-mnNXr-Q&e=
https://urldefense.proofpoint.com/v2/url?u=https-3A__docs.microsoft.com_en-2Dus_office365_securitycompliance_retention-2Dpolicies&d=DwMGaQ&c=1BXtvEoDZ8OoKVrbcaT-lQ&r=qicaA1ovBXCm8Njd06V_SDVuuC3_CleUzqCfATT-WQ4&m=urrPL1N2VLh_EzKrWw2gY3YxhdPY9ctc1_MFA2hDgjI&s=Hd6Rc21VVWO9e5nU9_Pi3BgKI96IW5Y_EJI6IKa1670&e=
https://urldefense.proofpoint.com/v2/url?u=https-3A__docs.microsoft.com_en-2Dus_microsoftteams_retention-2Dpolicies-2Dknown-2Dissues&d=DwMGaQ&c=1BXtvEoDZ8OoKVrbcaT-lQ&r=qicaA1ovBXCm8Njd06V_SDVuuC3_CleUzqCfATT-WQ4&m=urrPL1N2VLh_EzKrWw2gY3YxhdPY9ctc1_MFA2hDgjI&s=PuQMsD08zvJkixlcJ_G3lLfObE34nd1nIGSDyrw8ib8&e=