I believe they're talking about gradual typing[0].

[0]: https://en.wikipedia.org/wiki/Gradual_typing

Not really. Strongly typed languages don't usually support not having any types in your code (or any amount of gradual typing). At least not with any convenient syntax. There's usually some one clumsy "dynamic" type that doesn't interact with the rest of the system well and you'd be crazy to start writing your code using only this dynamic type.

I can't just write C++ like:

  any a = 1;
  a = "Hi!";