Comment by PhilMH SUBS:
I believe that the info in Discogs is reliable, as it appears to have come directly from the NZ company registry, which I have just looked at myself, and the following appears under the now-defunct company Universal Music Limited:
UNIVERSAL MUSIC LIMITED (14087) Removed
To maintain this company log on here
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POLYGRAM RECORDS LIMITED (from 01 Nov 1978 to 24 Nov 1999)
PHONOGRAM LIMITED (from 09 Nov 1972 to 01 Nov 1978)
POLYGRAM RECORDS LIMITED (from 25 Jun 1970 to 09 Nov 1972)
PHILLIPS RECORDS (N.Z.) LIMITED (from 14 May 1963 to 25 Jun 1970)
INTERNATIONAL PHONOGRAPHIC SOCIETY N.Z LIMITED (from 11 Dec 1961 to 14 May 1963)
Last updated on 03 Nov 2013
It's possible, indeed probable, that some of those "1972" NZ issues in Discogs showing Phonogram Limited fall into one of these possible categories:
(1) Represses/reprints of albums that were originally issued by the 1970-1972 iteration of PolyGram Records Limited;
(2) the usual discographical headache of assuming that the phonographic copyright (P) year is the release year - not necessarily the case, as that (P) year is set in the country where the recording is first issued, and other countries might issue it later, and also that (P) year should not change on represses and reissues.