Data retention information for Microsoft Defender for Office 365
By default, data across different features is retained for a maximum of 30 days. However, for some of the features, you can specify the retention period based on policy. See the following table for the different retention periods for each feature.
Defender for Office 365 Plan 1
* Alert metadata details (Microsoft Defender for Office alerts)
90 days.
Note: By default, the alerts queue in the Microsoft 365 Defender portal displays the new and in progress alerts from the last 30 days. The most recent alert is at the top of the list so you can see it first.

Reference:
https://learn.microsoft.com/en-us/microsoft-365/security/office-365-security/mdo-data-retention

Reference:
https://support.microsoft.com/en-us/windows/which-version-of-windows-operating-system-am-i-running-628bec99-476a-2c13-5296-9dd081cdd808

A user named User1 must be able to view all DLP reports from the Microsoft 365 admin center.
Users with the Security Reader role have global read-only access on security-related features, including all information in Microsoft 365 security center, Azure Active Directory, Identity Protection, Privileged Identity Management, as well as the ability to read Azure Active Directory sign-in reports and audit logs, and in Office 365 Security & Compliance Center.
Reference:
https://docs.microsoft.com/en-us/azure/active-directory/users-groups-roles/directory-assign-admin-roles

Explanation:

https://docs.microsoft.com/en-us/mem/intune/enrollment/enrollment-restrictions-set#change-enrollment- restriction-priority