This makes sense. For the same reasons you'd want your display driver written in a statically typed language like Rust. I think a good case can be made that Python(3) libraries should be using type annotations as well. Some net gains on software reliability that you may not want or need in your webapp, but is welcome in underlying libs.

While type errors are a small part of problems in software reliability, we should take everything we can get. At least in things thousands of millions of users are going to rely on.