This is not an accurate description of what happened. The information was in the release notes, which are several notches above EULAs for providing informed consent. Secondly, Debian doesn't install sotware, the user does. Debian helpfully provides the list of the packages and the versions before installing. There were no surprises here.
Additionally, contracts are not carte blanche to violate criminal law. To the extent that a contract provision would purport to allow violating a criminal law, it would be unenforceable.
You are filled with hatred and rage towards a project and you wish they'd be be sued to death by Oracle because of a minor package naming issue?
Same as in Debian. mysql-server is a transitional package which ends up installing mariadb-server package at the end.