If you have your documentation, you can try contacting Apple and talking about the issue. Every Mac have a serial number, so they can easily discover which account it is using and where it is.
They might ask for some police report proving that it where stole, though. Give it a try, it won't hurt. I hope you can recover your laptop!
It is my understanding the tracking is done via the apple credentials (email + password) as such it is unlikely that a permanent borrower of an apple device would activate a tracking beacon on the current usernames.
However as mentioned above, these items can often be traced provided you can prove that the item was stolen (police report) and you can prove you are the rightful owner (receipt). The downside is it usually requires a serial code that is only printed on the device in question.