Exchange Online and Exchange Online Protection service upgrade
Microsoft will upgrade all Office 365 customers, including Exchange Online customers, to the new version of Office 365. Exchange Online customer's email protection will be upgraded to Exchange Online Protection (EOP). There are a few topics that provide helpful information for upgraded Exchange Online customers on the Office 365 community wiki. These include the following:
Exchange Online and Exchange Online Protection Service Upgrade - FOPE Admin Center Access, which discusses access changes in the FOPE Admin Center.
Feature Differences Between FOPE and EOP, which describes behavior changes and feature differences between FOPE and EOP.
Service Upgrade Changes for Policy Rules, which covers differences between FOPE policy rules in the current version of Office 365 and Exchange Transport rules in the new version.
Log in to FOPE Administration Center After Service Upgrade, which explains how to sign in to the FOPE Administration Center after your service upgrade, if you want to reference your settings.
If you would like more information about service upgrades, Office 365 Service Upgrades and Service Updates is the best high-level source of information regarding service upgrades.