Microsoft is rolling out Built-In Protection to Defender for Office 365, a new feature that would automatically enable recommended settings and policies to make sure all new and existing users get at least a basic level of protection.  Microsoft Defender for Office 365 provides Office 365 enterprise email accounts with automated attack remediation and defends them from various threats, including business email compromise and credential phishing.

Once enabled, this feature will protect all existing and new end users across tenants from phishing emails with malicious attachments and links using Safe Attachments and Safe Links without requiring any actions from admins.

What Should You Do?
There is nothing that needs to be done as this feature will automatically upload.  The rollout for this new default security preset is starting this month and will continue to standard multi-tenants worldwide through the end of the year, reaching general availability in December.