Oracle Database is licensed by core not server, so in your example there is no reduction of license cost. Same total number of cores before and after the server consolidation. Power and cooling are non-linear savings as the new servers are working harder than the old servers. Rack space is saved and sys admin burden reduced. The dba's job is going to be equal or harder post-consolidation.
Storage is part of a server and should always be considered when upgrading or replacing a server. Your points about what differentiates server and storage consolidation are valid, but not exclusive. True, they can be done independently, but they can also be done together.
Storage advances often fuel server migration or consolidation. For example, transactional databases are notorious for wasting CPU cycles while waiting for i/o to complete, and replacing legacy storage with modern low latency storage can dramatically cut cpu utilization and allow for database servers to be consolidated. There is no savings here in terms of database licenses, however, because database vendors like Oracle and Microsoft don't pay refunds.
Biting the hand that feeds IT
