Access to a set of teams was revoked from your org app

Facts

Works with

Events API
{
    "team_id": null,
    "enterprise_id": "EXXXXX",
    "api_app_id": "AXXXX",
    "event": {
        "type": "team_access_revoked",
        "team_ids": ["T1XX3", "TXX34"]
    }
}

The team_access_revoked event is sent to your org-wide app when your token can no longer access a workspace in that organization—in other words, it's been uninstalled from a workspace.