The then mayor of Munich Christian Ude had to essentially endure bribing attempts by Steve Ballmer and Bill Gates in person to switch back to Windows. After 14 years the return to Microsoft happend after MS miraculously decided to move its German headquarters to the city and pay their juicy taxes there.

In the meantime, Munich had saved millions upon millions in licence fees. Fuck Microsoft and fuck corrupt politicians.

On the one hand I agree, it's not just the OS that's replaced, it's also the programs that run on it (unless they use cloud based apps, of course).

On the other hand, the Germany example you mentioned was 15 or so years ago. I imagine Linux has matured a lot since then.

Yes, the previous departments that shifted were mostly servers (Railways, Stock Exchange), tech-savvy people (unis) or light users (schools). This time a lot of normal desktop users are being asked to shift. So we'll have to see where it goes.