It is highly unlikely that the configuration file on one distro is replaced with one that was shipped on a different one. It may be a bit more likely that a config file is overwritten by a variant from a previous release, but I think this is still unlikely and I believe trimming the md5sum list is not a general practice for UCF managed configuration files.
As an example openssh-server ships the historical list, too: $ cat /usr/share/openssh/sshd_config.md5sum # Historical md5sums of the default /etc/ssh/sshd_config up to and including # 1:7.3p1-5. 0d06fc337cee10609d4833dc88df740f 10dc68360f6658910a98a051273de22c 11f9e107b4d13bbcabe7f8e8da734371 16c827adcff44efaca05ec5eea6383d7 2eeff28468576c3f2e538314e177687b 386c8b9079625b78f6d624ae506958ae 38fc7b31b3e3078848f0eec457d3e050 395c5e13801f9b4f17c2cb54aa634fbd ... -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to unattended-upgrades in Ubuntu. https://bugs.launchpad.net/bugs/1917677 Title: ubuntu: ucf tracking of valid known md5sums should be limited to only those md5sums that affect a given distro release Status in unattended-upgrades package in Ubuntu: New Status in unattended-upgrades source package in Bionic: New Status in unattended-upgrades source package in Focal: New Status in unattended-upgrades source package in Groovy: New Status in unattended-upgrades source package in Hirsute: New Bug description: Currently the project tracks all valid md5sums of permutations of 50unattended-upgrades.conf in a single md5sum file that contains every md5sum of every historic version of all unique distros: 50unattended-upgrades.Debian 50unattended-upgrades.Devuan 50unattended-upgrades.Raspbian 50unattended-upgrades.Ubuntu Ultimately ucf for a given packaging release should only track the applicable md5sums which are expected to be seen on that particular distribution and release. For example: On Ubuntu Bionic: valid md5sums should be limited to the md5sum of the most recent Ubuntu Xenial 50unattended-upgrades.conf and the md5sums of previous Ubuntu Bionic releases to allow Xenial->Bionic and Bionic->Bionic upgrades without prompt. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/unattended-upgrades/+bug/1917677/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp