Environment Access and Service Access in new Enterpise Cloud SKU

Summary

In old SKU, where we purchase epm products separately (but in same ID Domain), an ID Domain Administrator access superceded Instance Service Admin access. Did this change in new Enterprise Cloud SKU?

Content

In old SKU, where we purchase EPM Cloud products (like EPBCS, FCCS,ARCS) separately but in same ID Domain, an ID Domain Administrator access superceded Instance Service Admin access.ie, Domain admin can access the instance applications thru test and prod pods. Did this change in new Enterprise Cloud SKU? Is it true that ID Domain admin has access to environments and Instance Service Administrator access is required for accessing the applications? I have ID Domain Administrator access in new Enterprise Planning SKU, but not able to access the applications, unless i give myself other instance roles in addition..why would that be the case? Any clue?