Comment 2 for bug 1956115

/etc/default/motd-news as outlined in the link
"/etc/default/motd-news has an ENABLED=1 setting that if set to 0 will turn off this functionality."

The file no longer exists by default. This would be required to change the ENABLED variable from 1 to 0.
/etc/update-motd.d/50-motd-news notes the same thing in the code comments.
The directions or pulled location are wrong. ubuntu-advantage-tools requires MOTD which itself it does not control, both of which are not removable as they are dependencies of ubuntu-desktop-minimal. Subsequently there are forced hooks for MOTD and Apt for something most desktop users aren't using with the inability to opt out in the way it is listed.

The reason why this matters is a disabled service through systemd will then be enabled. By doing so it procs the running of said MOTD service which does reach out to the internet. The only certain option is to mask the services and timers entirely.

Since introduction, the totality of these files went from roughly 60-260KB in total to 3+MB.