I have seen his grave there :) It was renamed long time ago and the name is not contested neither by Germans nor by Russians (it’s not liked either, but the government abandoned the idea of renaming it back for symbolic reasons — it’s not about commemoration of Kalinin at all, nobody remembers him). Among Russians Koenig is indeed used as informal name akin to Piter (St.Petersburg) or Ekat (Ekaterinburg).
It's more like a running joke by now, giving Královec 'back' to the Czech Republic means they could finally have a proper overseas harbor and a Navy. Just think of the possibilities :)