Stencil's onSlotChange event is not fired when content changed

Stencil
1

Hi,
I found that slot exposes onSlotchange event. I guess that it is fired when slot’s children are modified. It is really helpful event for me but I’m not using it properly or it is not working as expected.

Here are minimal code snippets to reproduce:
→ index.html - uses slot-container and modifies it’s attribute’s value

<slot-container id="container" slottext="abc"></slot-container>
<button id="change">Change slot content</button>
<script>
    const changeBtn = document.getElementById('change');
    changeBtn.addEventListener('click', () => {
        const slotContainer = document.getElementById('container');
        slotContainer.setAttribute('slottext', new Date().toString());
}); 
</script>

→ slot-container.tsx - passes attribute to slot-component as children:

@Component({
    tag: 'slot-container',
    shadow: false
})
export class SlotContainer {
    @Prop() readonly slottext: string = '';

    render(){
        return (
            <Host>
                 <slot-component><p>{this.slottext}</p></slot-component>
            </Host>
        )
    }
}

→ slot-component.tsx

 @Component({
    tag: 'slot-component',
    shadow: false
})
export class SlotComponent {

    render(){
        return (
            <Host>
                 <div>Children:</div>
                 <slot onSlotchange={() => console.log('slots children modified')}></slot>
                 <div>dummy content</div>
            </Host>
        )
    }
}

Let me know if that code is not correctly or slotchange event should be subscribed somehow differently.