They would need to have a remote kill switch and use it.

Secondly, they have done this before (forced agreeing to the terms to do a software update) and every time they have warned "some functionality might cease to work" and every time I kept using it past the cutoff.

Once, I had Spotify stop working on me. I assume because they switched API keys or something.

In fact, for example, they had an update that killed Audible integration. And my Audible integration kept working until I installed the update.