Ah ah. Those discussions plague my calendar. For the moment, as far as I am concerned, SAP is promoting in S4 their own ontology, aka SAP CDSViews, which creates a looooot of questions in our domain. Is an external DB supplier supposed to force you into its own core data model. Just like if Oracle told you which tables you have the right, or not, to create.
S4 != HANA DB
The joke we have internally is that they expect companies to hire expensive SAP clean core experts to evangelize about what clean core is. == hey guys, hire us so we will tell what your dataModel/ontology should be.
Another side comment:
I am not that much in those platform stuff [,more in the enterprise data], but from what i understand, HANA failed to deliver the performances expected, whereas the marketing was MASSIVE.
So people are now a bit skeptical about any new move by SAP.