WhatsApp has stated that it will now allow users to back up their data (messages, audios and videos) with Google Drive independently. The info was made public on WhatsApp blog earlier. According to the blog, this will be possible starting from November 12, 2018.
This means that, from that date WhatApp no longer interfere with data that are back up in Google Drive. However, non updated data for more than a year will be deleted automatically from Google Drive automatically. To avoid this, you will need to manually back up your data on Google Drive on or before November 12 this year.
It also implies that if you change your phone you can retrieve all your data you have backup on Google Drive to WhatApp application on your new mobile phone. WhatsApp recommended that you backup your data with WiFi has this process usually result in additional mobile data charges.
To use Google Drive backup, your phone must have a google account on your phone, enough storage space and google play services. To create backups manually, go to WhatsApp, tap menu-->settings-->chat-->chat backup-->backup to Google Drive. Also select backup frequency. Note: Do not select "Never" as your back up frequency. You should also note that data backup by Google Drive are not secured by WhatsApp end-to-end encryption.