No[1], TypeScript is unsound in many ways. Most of them are intentional trade-offs to catch as many bugs as possible while not being too restrictive/allowing most JavaScript code to be annotated.

[1]: https://codesandbox.io/s/te0pn?file=/index.ts

Edit: Apparently TypeScript playground links cannot be shared :( Edit2: Published on codesandbox.io, hopefully that works