On June 1st, 2020, Microsoft Threat Protection will be automatically turn on when you hold one of the following licenses:
You can learn more about Threat Protection here https://www.microsoft.com/en-us/security/business/threat-protection/integrated-threat-protection
If you are eligible, you can turn on Threat Protection right now to the Security Center portal (https://security.microsoft.com/settings) and follow the steps outlined here https://docs.microsoft.com/en-us/microsoft-365/security/mtp/mtp-enable
If you are already using Threat Protection, no action is required from you and your current configuration will continue to as before.