Comment 8 for bug 1871801

The change was introduced on purpose, back in June 2011, when this was still part of the 'update-manager' package:
https://bazaar.launchpad.net/~ubuntu-core-dev/update-manager/main/revision/2140

Since then the corresponding code moved into the 'ubuntu-release-upgrader' package, where it resides today:
https://git.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/tree/DistUpgrade/DistUpgradeViewGtk3.py#n294

In the end we have to decide about whether it is more important to have the dpkg messages translated or be able to duplicate bug reports...

But here seems to also be another problem, which is unrelated to DPKG messages. The strings Igor mentions, such as "Do you want to start the upgrade?", which are displayed in the GUI, are part of the 'ubuntu-release-upgrader' code, not dpkg.

IMO it would be okay, or even appropriate, to show english strings/translations in the (embedded) terminal, as this is hidden by default and supposed to be used by advanced users, only.

However, the strings displayed in the main GUI should be displayed in the user's selected native language whenever possible.