Type-stripping, not TypeScript parsing or type safety.

Related:

Running TypeScript Natively in Node.js (59 points, 15 days ago, 34 comments) https://news.ycombinator.com/item?id=44597966

Node.js enables TypeScript handling by default (17 points, 6 months ago, 7 comments) https://news.ycombinator.com/item?id=42630790