Microsoft is making a free 90-day trial of Microsoft 365 E5 Compliance licenses available to tenants who don’t yet have compliance licenses. The purpose is to allow organizations to test the advanced compliance functionality which requires Office 365 E5 or Microsoft 365 E5 licenses. Microsoft obviously hopes that organizations will be so delighted at the functionality that they sign up for E5 licenses in the long run. If you don’t want to run a test in your production tenant, you can achieve much the same effect by getting an E5 trial tenant and testing there.
https://office365itpros.com/2021/09/28/microsoft-365-compliance-free-trial/
