I think holding that kind of power over devices people own is problematic, but I seem to be in the minority here.
You lose a trademark if it becomes generic, regardless of how hard you tried to keep it from being so. Obviously if you let a bunch of actual infringements slide you're on the way to becoming generic, but all that matters is whether the trademark IS generic.
But, when lawyers write letters to people saying "you can't say escalator or Zamboni" you can just ignore them. Using a trademark in writing in a way that a trademark owner does not like is not infringement.
I remember when the Apple logo stickers Apple packed in had a little (R), which was later dropped, since it's ugly and not legally required. But no doubt some lawyer advised putting it there to begin with.
[1] https://youtu.be/IzH54FpWAP0&t=530