I'm not saying this is the case at Uber, but it's quite common for MariaDB users to refer to it as MySQL, or to use the two names interchangeably. It's difficult to get out of the habit as all of the CLI tools are still mysql*, clients (i.e. the protocol) are all named "mysql", CM modules (like Ansible's) are all named "mysql", etc. And sometimes it's just simpler (if lazier) to say you're using MySQL rather than explain what MariaDB is and why it's preferable.