Microsoft is coming out with Update 9.0.2 for Dynamics 365 V9.0.
Microsoft has named it as Dynamics 365 Spring 18 Release.
Any new organization created on or after April 2, 2018 will be provisioned on the updated version. Any updates from version 8.x to version 9.0 that are scheduled on or after April 2 will automatically get this update, and no change of schedule is needed. For existing ORGs running Dynamics 365 (Online) version 9.0.1 or higher, Microsoft will start deploying this update starting April 7 through their normal deployment process.
This update is primarily focused on performance and reliability improvements, but it also contains some new features and capabilities. The new features are opt-in and will not change your default experiences.