For starters, WhatsApp remains end-to-end encrypted, which means your messages are safe. WhatsApp offers three updates: how the application handles your data; How businesses can use Facebook-hosted services to store and manage their WhatsApp conversations, and there will be further integration of other Facebook products with WhatsApp.
If you delete your WhatsApp account directly from the application, it will not mean that your data has also been deleted. The policy states: "When you delete your account, this does not affect your information about the groups you create or the information that other users have for you, such as your copy of the messages you sent them." You will have to dig deeper to clear your WhatsApp data if you want to delete your account.