Stephen Usher pointed it out earlier. The cloud servers are Amazon AWS. That means they're using Linux.
It was stupid of me not to realise it before. Porting that to Windows in any form would be a sizeable undertaking. Even mocking it out would be challenging.
Offline mode was dead as a concept the moment they made those technical decisions - which happened very early on in development.
So I re-iterate. They've known about this for a long time.
Sorry but the evidence you present for your logical conclusion is lacking, you may well be right, but you are just guessing.
Porting Linux code to Windows can range from trivial to difficult, depending on many and varied factors, (I have to maintain and advance a large multi-node 3D engine framework that supports pretty advanced HLSL/GLSL shaders across both Linux and Windows written in C++).
- C++ is mostly trivial to port from Linux to Windows and vice versa, even when going from a VS environment to Linux Makefiles it really isn't that difficult and you can always use tools like CMake.
- GUI, 2d/3d graphics, the more of this your application has, the more difficult, (potentially), the porting can be. If you use standard API's like Qt and OpenGL then it may not be difficult all: typically your server code has little or NO GUI/2d/3d, just a console and some log files.
- If you spend just a few hours in planning when you start your project you can have a parallel version of Linux and Windows code compiling and running side by side trivially.
- Worst case for an application that had no forethought put into it; (in my experience), most non graphical applications could be ported from one to the other in a matter of weeks, with Linux to Windows being faster than Windows to Linux. This is a sweeping generalisation because it depends on so many factors, (how the code was written, what compilers/linkers/tools used, what API's used etc), but it's usually not more than a 1 man job and never impossible.