I agree with you, @borishag.  Those tags are not necessary.  This changeset is a mistake and has been reverted now.

That said, "addr:city" and "addr:postcode" should also be deleted all across Belgium, because we have zones covering the country to provide this information much more reliably.

When cleaning up data, I currently make an exception for AS Watson shops because I understand that you regularly query OSM data and expect to find city name and postcode directly on the nodes instead of doing geoqueries.  It would be nice if you could find a way to improve this in the future.