In Russia there are plenty of new options like Kazan for example. In Czechia Brno or perhaps Plzeň. As for countries that haven't hosted recently there would also be possibilities like Great Britain or Norway.
Regarding Russia: 80% of the population lives in the European part of Russia and the two largest cities are Moscow and St. Petersburg. If the Russian Hockey Federation thought they could sell more tickets by having it in Kazan or Omsk, they would.
Regarding Czechia (it will take some time to get used to that name): Prague and Ostrava hosted the best and fourth-best attended Championships. Why change?
Do Great Britain and Norway have the venues capable of hosting the event? I would be surprised if they did.
I would, however, like to see the Championship come back to Germany soon.