No.

TypeScript 73.9% JavaScript 21.6% CSS 3.4% Inno Setup 0.8% HTML 0.2% Shell 0.1%

Do you have any references for this? I believe most are of the impression that VSCode run entirely on electron/node; even the editor, Monaco, which is written in JS.

Although, I believe their plugin system would allow plugins to be written in any language.