Comment 1 for bug 1581044

> The problem is that this causes an unnecessary conffile prompt on upgrade from Wily to Xenial.

This is a problem for non-interactive upgrades, such as scripts, as well as during possible SRU updates of packages whose conffiles have been modified. On servers, automation is common, and does not know what to do. Either the conffile modification will be overridden, in which case shipping it modified becomes pointless, or the old modified conffile is left active, in which case SRUs cannot fix up user-unmodified conffiles if that is necessary.