The "componentWillReceiveProps" and "componentWillUpdate" lifecycle methods are going to be deprecated in React v16. These methods will be replaced with new lifecycle methods that are more efficient and easier to reason about. The new methods are "getDerivedStateFromProps" and "getSnapshotBeforeUpdate".

In React Router v4, you can get the history object by using the "this.props.history" object passed to the component. This object contains the current history of the router, including the current location, previous locations, and navigation history. You can use this object to programmatically navigate, access the current URL, or manage the browser history.

To dispatch an action on load, you can use a lifecycle method in a React component, such as componentDidMount(). This method is called once the component has mounted, allowing you to dispatch an action to the Redux store.

The main difference between Flow and PropTypes is that Flow is a type checking tool for JavaScript that checks types at compile-time, while PropTypes is a runtime type checking library for React components that checks types at runtime. Flow is particularly useful in large codebases where it can be difficult to keep track of all the variables and function calls, while PropTypes is useful for catching errors in React components at runtime.

The suspense component is a component for delaying rendering in React. The suspense component allows components to wait for asynchronous data to load before rendering, improving the user experience and reducing loading times. The suspense component is typically used with code splitting and lazy loading to enable on-demand loading of code.

ReactDOM is separated from React in order to improve performance and reduce the bundle size of React applications. Separating the rendering logic from the component logic allows for more efficient updates and reduces the amount of JavaScript that needs to be downloaded by the client. This separation also allows for easier integration with other rendering targets, such as native mobile apps or desktop applications.

Lifting State Up is a technique in React for passing data up from child components to parent components. This is useful when multiple components need to share the same state or when a child component needs to update the state of a parent component.

In Create React App, you can include polyfills to support older browsers by using the "core-js" library, the "@babel/preset-env" package, or the "react-app-polyfill" package. These packages provide polyfills for various ES6+ features and browser APIs, and can be configured in the "babel.config.js" or "webpack.config.js" files.

React has several advantages, including improved performance, reusable components, and good community support. React's use of a virtual DOM and its focus on component-based architecture help improve performance and make it easier to develop complex UI components. React's component-based architecture also makes it easier to create reusable components that can be used across multiple projects. React has a large and active community of developers, which provides good support and resources for learning and development.

Keyed Fragments are a feature in React that allows elements to be grouped together without adding extra nodes to the DOM. This can improve performance and reduce the complexity of the component hierarchy. Keyed Fragments are created by using the element and adding a unique key prop to each child element.