Difference in overload pick between JS and TS with default generic type parameter

[IllusionMH]

TypeScript Version: 4.0.0-dev.20200703, 3.9.2 (playground)

Search Terms: js ts overload difference, javascript different overload, javascript wrong overload, javascript overload generic empty object

Code
definition.d.ts

export class EmptyObjectOverloads<T = {}> {
    constructor(a: Readonly<T>);
    /** @deprecated */
    constructor(a: T, b?: any);
}

export class RecordOverloads<T = Record<string, any>> {
    constructor(a: Readonly<T>);
    /** @deprecated */
    constructor(a: T, b?: any);
}

ts-example.ts

import { EmptyObjectOverloads, RecordOverloads } from './declaration';

class TSExampleEmpty extends EmptyObjectOverloads {
    constructor(a: any) {
        // hover over super: constructor EmptyObjectOverloads<{}>(a: Readonly<{}>): EmptyObjectOverloads<{}> (+1 overload)
        super(a); 
    }
}

class TSExampleRecord extends RecordOverloads {
    constructor(a: any) {
        // hover over super: constructor RecordOverloads<Record<string, any>>(a: Readonly<Record<string, any>>): RecordOverloads<Record<string, any>> (+1 overload)
        super(a);
    }
}

js-example.js

class JSExampleEmpty extends EmptyObjectOverloads {
    /** @param {*} a */
    constructor(a) {
        // hover over super: constructor EmptyObjectOverloads<any>(a: any, b?: any): EmptyObjectOverloads<any> (+1 overload)
        super(a); // deprecation warning '(a: any, b?: any): EmptyObjectOverloads<any>' is deprecated ts(6385)
    }
}

class JSExampleRecord extends RecordOverloads {
    /** @param {*} a */
    constructor(a) {
        // hover over super: constructor RecordOverloads<Record<string, any>>(a: Readonly<Record<string, any>>): RecordOverloads<Record<string, any>> (+1 overload)
        super(a);
    }
}

Expected behavior:
Both TSExampleEmpty and JSExampleEmpty pick same overload similar to TSExampleRecord and JSExampleRecord.

Actual behavior:
TSExampleEmpty uses default generic value {} and picks first overload.
For JSExampleEmpty generic value to is any and second (deprecated) overload picked, while JSExampleRecord works as expected.

In real world examples this behavior marks all super(props); in React class components in JS files as deprecated.
Of course it's impossible to report TS issue without mentioning React 😆 related constructor declaration

Playground Link:
Example TS Example JS

Related Issues: Haven't found any

[DanielRosenwasser]

I vaguely recall generic defaults being treated differently in JS mode.