That's not true of Pods; each Pod has its own distinct network identity. You're correct about the network, though, since AFAIK Service and Pod CIDR are fixed for the lifespan of the k8s cluster
You spoke to it further down, but guarded it with "likely" and I can say with certainty that it's not likely, it unconditionally does. That's not to say address re-use isn't possible over a long enough time horizon, but that bookkeeeping is delegated to the CNI
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Your "dead container" one also has some nuance, in that kubelet will for sure restart a failed container, in place, with the same network identity. When fresh identity comes into play is if the Node fails, or the control loop determines something in the Pod's configuration has changed (env-vars, resources, scheduling constraints, etc) in which case it will be recreated, even if by coincidence on the same Node