Well if tickets bought the ticket prior to administration, if you received a refund would have been an unsecured creditor and received around 10 cents in the dollar, so what customers have been offered is much better.
The credit is for
Virgin Australia services and there’s likelyhood there maybe new destinations opening up in which the credits would still be valid. This is also partly why the have a long expiry.
Depending on the company direction, there’s the possibility of different international destinations.
What gets forgotten often with these international trips, you should get appropriate travel insurance in which would trigger a claim / refund excluding an excess from insurance. It’s that simple.