This is a commercial extension: "Given C# Dev Kit builds on the same foundations as Visual Studio for some of its functionality, it uses the same license model as Visual Studio."
You have to sign in with a Microsoft account to use the new C# Dev Kit extension in VS Code.
This is true, but might be misleading. It follows the Visual Studio Community license so if I'm reading it correctly there's no cost to use it for individuals, open source organisations, and for up to 5 users at small/medium non-open source organisations.
That's even worse that it works under the Community terms, as if one of your employees installs it you can be liable for license costs if you have 6+ employees or make 1mm. MS license auditors will be having a field day.
EEE in full effect
If Microsoft -- with it's billions -- can build something better than the community and offer it for free, I have nothing against it. I wouldn't really consider this EEE in the classical sense. C# being a key platform component and having OmniSharp coming up short was always odd.