How about being stuck on a road in a snowstorm without communication? There are reasons why we shouldn't disable people's phones. I would argue for nagware - every hour, have a message pop up telling you there is a safety issue and asking you to return your phone to a Verizon store for a free replacement or something. Seems like a good balance between keeping devices safe and people losing critical communication.
I would argue (as someone who had the Note 7 and returned it over 1.5 months ago) that the time for minor annoyance popups is over. I think it should be more like you get a permanent popup that asks you to return the phone and that only the phone dialer & contacts app works on the phone so you aren't stranded. I get wanting to keep the Note 7 (best phone I ever owned other then the whole fire issue) but at this point you are putting others at risk because you don't want to give it up.