I just came up with an untested theory of the push to retain you at a rate no matter what.
Background. I was helping my dad get the lowest rate possible and keep renewing him each year on his 2009 Sonata. Dad stopped driving in 2019 and I sold the car to a friend. The friend never paid for XM yet the radio is active. I have a previously owned 2020 Honda Ridgeline. I was going to transfer the subscription that I had on my previous Honda Accord that I renewed each year since 2006 but wanted to wait until the subscription on the new truck no longer worked. Now it has been over a year since I bought it and it still works.
Which comes to my theory. What if on some vehicles, they do not know how to turn them off. What if they only know how to activate them but do not know how to purge radios from the system?
Can someone who is thinking of renewing on an older vehicle, wait it out and see if their radio still works after their sub ends and not renew?