Readonly vs. litteral type breaking change?

[stephanedr]

TypeScript Version: 2.1.1

Code

class A {
    readonly n = 0;
    constructor() {
        this.n = 1;  // Type '1' is not assignable to type '0'
    }
}

class B {
    constructor(readonly n = 0) {}
}

class C extends B {
    constructor() {
        super(1);  // Argument of type '1' is not assignable to parameter of type '0 | undefined'.
    }
}

Expected behavior:
Is this behavior expected (breaking change vs 2.0.8)?
To me this should be valid, particularly the 2nd case.

Actual behavior:
Errors displayed in comments.

[falsandtru]

#11409

[mhegazy]

All parameter initializes should be widened to their base (e.g. class B), property initializes (e.g. class A) are intentional breaking change.

[sandersn]

Fix is up at #12312