The method updateIPsForName will not return true in case of expired DNS entry. The logic in this function as follow:

• Lookup for dnsname
• update newIPs
• Another lookup
• Finally compare
  The Lookup will exclude always the expired entries. The impact is no update for rules in case of some expired entries. Is that intended?

https://github.com/cilium/cilium/blob/master/pkg/fqdn/rulegen.go#L525