[3.2.0.12]Problem detected by "zypper ve" after upgrade

I don't even have zypper installed on my J1 with that OS version, did you install it manually?

AFAIK zypper needs to be installed manually, but generally works fine & I have been using it as well. By default only Packagekit and it's CLI tools (pkcon) are available.

While this looks slightly wrong at the package (management) level, I wonder if this has any impact.

You may take a look at the corresponding files and symlinks, if they look similar to those on a Jolla 1 with SailfishOS 2.2.1:

[nemo@sailfish ~]$ ls -l /etc/*-release
lrwxrwxrwx 1 root root  16 2018-11-04 04:43 /etc/hw-release -> /etc/sbj-release
lrwxrwxrwx 1 root root  16 2018-08-30 19:37 /etc/os-release -> sailfish-release
-rw-r--r-- 1 root root 211 2018-08-30 19:37 /etc/sailfish-release
-rw-r--r-- 1 root root 198 2018-08-30 15:52 /etc/sbj-release
[nemo@sailfish ~]$ cat /etc/hw-release
NAME=Jolla
ID=sbj
VERSION="1.0.1.11 (armv7hl,unknown)"
VERSION_ID=1.0.1.11
PRETTY_NAME="SbJ 1.0.1.11 (armv7hl,unknown)"
SAILFISH_BUILD=11
SAILFISH_FLAVOUR=unknown
HOME_URL="https://sailfishos.org/"
[nemo@sailfish ~]$ cat /etc/os-release
NAME="Sailfish OS"
ID=sailfishos
VERSION="2.2.1.18 (Nurmonjoki)"
VERSION_ID=2.2.1.18
PRETTY_NAME="Sailfish OS 2.2.1.18 (Nurmonjoki)"
SAILFISH_BUILD=18
SAILFISH_FLAVOUR=release
HOME_URL="https://sailfishos.org/"
[nemo@sailfish ~]$

I.e., hw-release contains the version information for the originally installed SailfishOS releases and os-release for the currently installed one.

A zypper verify --dry-run -y on this Jolla 1 with SailfishOS 2.2.1 shows no such complaint (as described in the OP).

Yes, I see the same on an Xperia X freshly upgraded to SailfishOS 3.2.0.12:

[root@sailfish ~]# zypper verify --dry-run -y
Loading repository data...
Reading installed packages...

Problem: product:# This file is copied as hw-release-0.2.1.15.analogous to os-release is not installable
Solution 1: deinstallation of product:# This file is copied as hw-release-0.2.1.15.analogous to os-release

Choose the above solution using '1' or cancel using 'c' [1/c] (c): c
[root@sailfish ~]# ls -l /etc/*-release
-rw-r--r-- 1 root root 296 2019-10-23 13:33 /etc/hw-release
lrwxrwxrwx 1 root root  16 2019-10-23 13:54 /etc/os-release -> sailfish-release
-rw-r--r-- 1 root root 209 2019-10-23 13:54 /etc/sailfish-release
[root@sailfish ~]# cat /etc/sailfish-release
NAME="Sailfish OS"
ID=sailfishos
VERSION="3.2.0.12 (Torronsuo)"
VERSION_ID=3.2.0.12
PRETTY_NAME="Sailfish OS 3.2.0.12 (Torronsuo)"
SAILFISH_BUILD=12
SAILFISH_FLAVOUR=release
HOME_URL="https://sailfishos.org/"
[root@sailfish ~]# cat /etc/hw-release
# This file is copied as hw-release (analogous to os-release)
NAME="Sony Xperia X"
ID=f5121
MER_HA_DEVICE=f5121
MER_HA_VENDOR=qualcomm
VERSION="0.2.1.15 (armv7hl)"
VERSION_ID=0.2.1.15
PRETTY_NAME=" 0.2.1.15 (armv7hl)"
SAILFISH_BUILD=15
SAILFISH_FLAVOUR=release
HOME_URL="https://sailfishos.org/"
#

In addition to the package conflict (or as a result of it), the content of the file hw-release looks odd, with the version numbers consistently being set to the package version (autogenerated?), but not any extant SailfishOS release version. But maybe it indicates some hardware adaption layer release number nowadays.

Still I believe that this is a rather minor nuisance with likely no significant effects.