Microsoft is working on improving Microsoft Defender for Office 365 with priority protection features for high-profile employees like executive-level managers that threat actors target most often. The feature is currently in public preview and Microsoft plans to make it generally available to all customers with Microsoft Defender Advanced Threat Protection in November 2020. Microsoft is also working on including SMTP MTA Strict Transport Security (MTA-STS) support in Exchange Online to secure Office 365 customers’ email communication security and integrity starting with December 2020.
Source: https://www.bleepingcomputer.com/news/security/microsoft-adds-protection-for-critical-accounts-in-office-365/