I can tell you at the enterprise level, Cloud services were absolutely pushed as a cost savings measure. All the math in the world can't save you from a determined C-suite, however.
We just finished our migration to the Cloud after 3 long years of effort, and while we are saving about ~2MM/mo in data center costs, our opex spend is up by around 2.5MM/mo YoY, not including all the Cloud-centric new hires.