According to ZDNet, this is not the first time that WhatsApp has warned that backups are not encrypted. But it is a warning worth repeating considering the useful nature of being able to back up your chat history. This is especially important now that WhatsApp and Google have announced that backups won’t count to your Google Drive storage quota starting 12 November 2018.
WhatsApp will also permanently delete of any backup that hasn’t been updated for a year or more. So if you’d like to keep your chat history intact, you’ll have to make another backup as soon as you can before that date. While your WhatsApp conversations will not be as safe in Google Drive as they will in your phone, you can still make it harder for those who intend to snoop around where they don’t belong. Just make sure you enable two-factor authentication for your Google account. (Source: WhatsApp via ZDNet)