I think the below should be allowed.

class A {
    protected constructor() {

    }
}

class B extends A {
    static create() {
        new B(); // ERROR, but should not error.
    }
}

I wanted to override a static factory and customise it a bit. But it seems like I wasn't allowed to do it.

And my motivation is that private constructors are accessible on a class's static methods.

class A {
    static create() {
        new this();
    }
    protected constructor() {

    }
}

And a natural extension of the private case is to allow protected constructors on subclasses's static methods.