Deleted chats are still recoverable.
After the whole debacle of WhatsApp turning on end-to-end encryption by default, it was revealed that the app isn’t completely erasing chats when deleted and could still be recovered.
The flaw was found by Jonathan Zdziarski, who discovered the flaw. Apple Insider reported that the only way to omit any traces of deleted chats is to completely delete the app – though traces of a particular chat will still be present, but will be overwritten once the app has been reinstalled.
Zdziarski made a detailed post on the issue, citing that the issue is also present on Apple’s iMessage. “The WhatsApp chat database gets copied over from the iPhone during a backup, which means it will show up in your iCloud backup and in a desktop backup. Fortunately, desktop backups can be encrypted by enabling the “Encrypt Backups” option in iTunes. Unfortunately, iCloud backups do not honor this encryption, leaving your WhatsApp database subject to law enforcement warrants,” he mentioned.
There is also a chance that data can be copied if you have an unencrypted backup of the app stored on your computer.
They say it shouldn’t be a cause of concern – though WhatsApp hasn’t released a statement on the matter.