Not really semantics, more facts. You can use it as a freesat box after you have left Sky, (or upgrade to Sky Q), and you can sell it on, go round any car boot sale and you'll see plenty.
Just because it was free doesn't make it any different to any other electrical goods you have.
I have never had to pay for a call out either, but the equipment is yours, given as a freebie when you sign up or upgrade, which is why if it goes wrong in the first year it is fixed for free under guarantee. You do not pay rental for it, you pay for the TV service.
This is the opposite of...