The code output is really clean; I wouldn't call it obfuscated. Especially when source mapping works just about everywhere.
And having ES2015 features (+async/await) is very useful: var should be deprecated, arrow functions should be standard, etc.
Tiny projects? Sure, do whatever you want. But I've started switching even my one-file, 2-3 screens of code Node servers over to TypeScript, and it's not only useful, it accelerates development by 100% simply because you don't need to run your code to know that you've got the types correct.
I stand by "best practice."