Hey!
First, no false promise: even with better type systems (like Scale) the real safety comes with tests (unit, functional, integration, code reviews, etc.).
That said, I've used (and am using) Typescript for web services, as well as Scala, and, in a typescript-versus-javascript perspective, I would say that TS definitely helps. I mean: the type system is not strictly typed, but duck-typed, and will not save you from errors. But it does help a lot for refactor and documenting your code. Hence, it also helps a lot for code reviews, and it's easier for your peers to get into your code, because of what I'd call the "documentation by interfaces".
Please keep in mind that I was an early adopter of TS and therefore am very biased. But what was "the edge" at the beginning of Typescript 2 years ago is now standard ES6 (all that to say that if you look at the arguments of people against TS, many of them are now embracing ES6 and the syntax they were rejecting because of "not yet another new thing").
Bottom-line: Typescript is not strictly type, and will let you do errors. But when the Node stack is relevant (performance wise), from a safety perspective it's way better, especially if you're working in a team.
If you like, I could share my current dev toolbox to give you an idea.