There’s a useful “Microsoft Dynamics 365 Existing Customer License Transition Guide” released from Microsoft with information on: options for customers now that CRM Online SKUs are no longer available, how and when you can upgrade to Dynamics 365 with existing CRM Online licences and what use rights you get in a mixed deployment, who’s eligible for the special transition SKUs for how long, and when Add-on and From SA User SLs are the right thing. It’s here with the rest of the excellent Dynamics 365 Licensing Guides: http://bit.ly/MSLicensingGuides.