[alimbada]

All APIs need good documentation to be good APIs. If you're not providing good documentation with your API you're doing your users/consumers a disservice. Using a tool (TypeScript/Flow/whatever) to ease the pain of providing that documentation is in the best interests of an API developer since it reduces the friction of having to write the documentation by hand. Also, in this case, good documentation is not just documentation for the programmer that is consuming the API, but also the IDE within which the API is being consumed.

I'd say in this situation the title is justified.