While the idea sounds great in theory, it looks like (at present at least, on the Windows side,) this relies on a install of Windows Server 2016 Core (which is further stripped down by removing language packs and such.)

The issue for most people I think, is there seems to be very little adoption of Server Core.  I came across a thread on Reddit over the weekend (r/Sysadmin) where someone was indicating the main reason they don't use Core is there's no good substitute for Device Manager (and that includes PowerShell,) making it very difficult to update drivers or install drivers.  Personally, when we were planning our migration to Windows Server 2012R2 / SQL 2014, I was very tempted to go to Core simply to reduce the monthly patching I have to do.  Unfortunately, many of the required software we have to have on our servers, won't work / install on Core...

Perhaps if MS can improve the tooling for managing Core installs, we'll see more organizations start using it, and then we'll start to get "zero" downtime patching...

But I'm not betting on it being soon.