Microsoft seems to want to release feature updates for their software twice per year, once in the fall, and once in the spring. First, Office 365 announced that it would adopt a semi-annual schedule, targeting September and March, give or take a bit. The Windows team then announced that they would follow in Office’s footsteps.
It’s interesting, because Windows Server typically pushes out two major versions every four or five years: one with a number, and another with that same number alongside an R2 suffix. Each of these lines up with a consumer refresh of the NT kernel, although both Windows Server 2003 and Windows Server 2003 R2 used the same kernel… because Windows XP lasted a while.
Sure, a lot of a name would normally be marketing, but it also gated the major features that Microsoft was able to add (because they wanted a single Windows release to interact with software fairly uniformly across its lifecycle for enterprise reasons). Now, with the whole company pushing the “as a service” model, even Windows Server will be on the feature release treadmill.