Well all inhabitants were pretty much thrown out or fled to Germany in fear of persecution. Then Stalin filled it up with ethnic Russians.

They do have their own identity afaik, but it stems more from the connections they made with the neighbours: Lithuania and Poland.

I don’t know how deep it goes, but Kaliningraders were more against the war as it inconvenienced them in doing their shopping in Lithuania.

Btw it’s only half of East Prussia, the southern half was given to Poland.