https://arstechnica.com/information-technology/2019/06/the-c... gets into the crypto side of it.
So yes, information about location is being sent to Apple. No, it's not useful for Apple and it is encrypted in a way that Apple can't get it the underlying data.
> Apple returns the encrypted location of the laptop to your iPad, which can use its private key to decrypt it and tell you the laptop's last known location. Meanwhile, Apple has never seen the decrypted location, and since hashing functions are designed to be irreversible, it can't even use the hashed public keys to collect any information about where the device has been.
To sibling commenter: my comment is based on a correct understanding of Location Services, not on anything to do with Find My Device. You don't have to put words in my mouth, especially when I have already explained it using my own words elsewhere in the thread.
Impressed they can do that when I’m using offline mapping in an area with no mobile signal.