I noticed that too. It seemed to die about 12 hours ago but is back now (came back overnight for me and hence I don’t know exactly when it came back).
DNS lookups were giving SERVFAIL when addressed indirectly and timing out when addressed directly to any one of the three name servers.
This (puri.sm domain outage) has happened multiple times before. An earlier discussion gives some alternative domains but I didn’t test any of them during the outage.
I don’t know the answers to either of your questions.