CodeSystem OID stil required to support existing applications using various HL7 standards (v2, v3, CDA). Also required to support applications in the context of IHE profiles using OID.
I believe these 3 are still essential, the only argument is version might not be useful in situations where there is a live update rather than batch update but that is minor.
At a past HL7 Community call, there was a suggestion to have the Terminology Gateway display the CodeSystem OID along with the CodeSystem URI. Currently, information regarding a subset is tabulated with the following:
1. Name of CodeSystem
2. URI of Codesystem
3. Version
Just wanted to seek the community's feedback on whether there is any impact to usage and if it indeed warrants a change.