[tokyodude]

Apple knows which is how they can display every devices location on icloud.com including "last known location" which means the location was previously sent to Apple.

[xenadu02]

That requires you to opt-in to the “Find My iPhone” or “Find My Friends” feature which are explicitly designed to locate the phone.

If you don’t enable those things (which are not automatically enabled) then Apple does not know the location of your phone.