There's a history of German public administrations using Linux and other open-source software. In particular, the City of Munich has pioneered this with their 2006-2019 LiMux [0] project, which was ultimately cancelled in exchange for Microsoft moving their German offices to Munich proper.
[0]: https://en.wikipedia.org/wiki/LiMux / Discussion at https://news.ycombinator.com/item?id=15661372
Munich seems to have become the preferred destination for US companies opening their German office (most recent: OpenAI, Notion, Anthropic).
So if Microsoft would have paved that way, it would have been totally worth it for the city.
Back then Microsoft was lobbying as hard as they could to turn that decision to move to linux over.
They knew: If Linux makes it in Munich, it will likely spread over and they loose tons of contracts with other German states.