Is it coming or not?

The new version for version 9.x will coming in October for on-premises customers. At time time, the version number will be 9.0.2.

Microsoft says:

The new update—Microsoft Dynamics 365 for Customer Engagement apps, Version 9.0.2, On-premises update—will release in October 2018. Customers currently in “December 2016 Update for Dynamics 365” (Microsoft Dynamics 365 version 8.2) can update to this version once it is available.

The next update to Microsoft Dynamics 365 for Customer Engagement on-premises apps is coming in October, bringing a brand-new user experience among a host of new and updated capabilities. The Unified Interface is a new metadata driven client interface that provides consistent experiences across all applications, devices, and form factors.

The complete list of features is available here

The cloudblog article at Microsoft is available here