Significant Locations in iCloud backup under iOS 14

Background:

Significant Locations are found under Settings > Privacy > Location Services > System Services > Significant Locations.

Basically it's tracking every place you are visiting frequently, such as your work, home, school, girlfriend's parent's home, etc.

These have historically not been included in iCloud backups.

If this has changed (looks like that based on the investigation in this post), this is important because Apple are not using end-to-end encryption for iCloud backups, putting this fairly personal data at risk.