distro-info-data package outdated but some unattended upgrades are taking place

I am noticing the following entry in my /var/log/unattended-upgrades/unattended-upgrades.log

WARNING Could not figure out development release: Distribution data outdated. Please check for an update for distro-info-data. See /usr/share/doc/distro-info-data/README.Debian for details

However sporadically, among those entries there are some other ones that indicate that some security patching is indeed taking place; for example

INFO Packages that will be upgraded: wget
INFO Writing dpkg log to /var/log/unattended-upgrades/unattended-upgrades-dpkg.log
INFO All upgrades installed

What is the case here? Is the distro-info-data up to date or not? if not, how come fore example **some** updates are taking place?