class default export makes private fields "unused"?

I am not sure if this is a bug, but it irritates me a lot. When I make this class a default export I get the below warning (unused field “bar”).

Can anyone reproduce this? Why is this?

export default class Foo {
  private bar = "";
  
  init() {
    this.bar = "baz";
    return this.bar;
  }
}