> ... If message is passed as a prop to any child components, Vue knows that they depend on this will be automatically re-rendered as well. That’s why there’s no need for a shouldComponentUpdate method on Vue components.

I think that React does the same? If a component's props and state don't change, shouldComponentUpdate doesn't get called at all IIRC. shouldComponentUpdate, instead, is useful when a state or prop was changed, but it's possible to quickly detect that the change won't require a DOM update anyway.