They effectively raised the cost significantly for perpetual licensing/SA to push you into services agreements. Simultaneously, you get favorable terms (ie. anything other than MSRP) only if you commit long-term. Upon renewal they try to make you give up your right to transition back to perpetual licensing for Office.
So my bet is this is bullshit, shifting office dollars to O365, which include plans where you're just renting Excel.
Sure it is, I have no doubts about it's growing use. But that use is still in nascent stage so when Microsoft is reporting a sudden increase in cloud revenue is actually nothing but smart manipulation of ELA terms.
In reality Enterprise Customer aren't cloud ready . Simply running on premises virtual machines into cloud does not result in any benefits. Enterprise customers are not yet there to realize the cloud benefits like on-demand compute, containerization, resource right sizing. Though Windows 2016 might tip that balance.
In last quarter, I personally suggested to few friends at Microsoft stack dependent companies to migrate to Azure instead of mucking around with colo hardware, VMware, VM management, licensing etc. for external facing services. It is a change for me. Previously I used to suggest moving to Linux/open source stack to migrate to VPS providers or AWS.