I now routinely install fake-ubuntu-advantage-tools.deb to remove Ubuntu "Advantage". It's an empty package that satisfies the dependencies.
I also remove some of the crap that Ubuntu put in /etc/update-motd.d. From memory 10-help-text, 50-motd-news, 88-esm-announce, 91-contract-ua-esm-status are pointless and annoying.