I have well over 60 2star wolves.
It's my understanding that while taming them if you abandon them, they will despawn.
Once tamed, interacting them toggles them from "stay" and "follow". They will never despawn.
They may be in a limbo state when you breed them. Where they have no "stay" or "follow" command so they kinda wander. Same when they are cubs. This can lead to wandering tamed wolf packs that clear out your woods and auto breed after killing dear/boars.
Pretty sure 2stars only spawn at night. Took me several to get a single one to spawn. Taming process worked day or night. I stayed just outside of agro range so that he'd eat and tame.