Yeah, those old *.mu.oz.au subdomains seem to have steadily disappeared. When my eldest brother was there somewhere around 2005–2010 Computer Science were still actively using cs.mu.oz.au (I think all their email and web stuff was still there), but even that seems to have lost its A records now, though it’s still got a third, interesting NS record (compared to ee.mu.oz.au which has only two boring NS records, edns-*.unimelb.net.au), mulga.cs.mu.oz.au, which is still talking A.

Another bit of historical trivia that now becomes mundane: csiro.au.