Google told the reason behind the delete the location history
Google Maps: If your data was backed up on Google Cloud, then you can easily recover it, but if you did not turn on the cloud backup setting, then your data has been deleted forever and it is not possible to get it back.
Google Maps is the largest and most used navigation application present today, but sometimes there are some problems with it too. The latest example is of Google Maps history being deleted. Actually, a few days ago Google Maps users' location history was deleted. Google has also officially recognized this problem with Maps.
Google clarified in a release to the English tech news site The Verge that it was a technical problem, due to which the timeline information of some of its users got deleted, though the company was not clear as to how many users this problem is affecting. Your information is easily recoverable if it was saved on Google Cloud, but if you haven't activated the cloud backup feature, your data is lost forever and cannot be recovered.
How to check if your Maps data is safe?