mysql 5.6 FEDERATED table and mysql.servers correlation

I have no expirence with FEDERATED tables in MySQL. I have database with FEDERATED tables defined and I'm wonder if this tables are used in current env (I have no access to application/developers to ask/check). The mysql.servers table (https://mariadb.com/kb/en/mysqlservers-table/) is empty. I wonder if connection info stored there is ephemeral or persitent after first connection to remote server/s. My question is: if mysql.servers table is empty can I "safely" assume that this tables are not used by apps?