You are right to think that the expression is old. It comes from the time when information in small places was given by the [town crier][2].

> A town crier was a person whose job was to make official announcements in a town or village by calling them out in public.

[The website Axiomcafe][1] gives an explanation on the expression's origin in France:

> L'expression 'dernier cri' remonte en fait au temps où ni la télévision ni les journaux n'existaient, et où les infos exclusives étaient criées sur la place publique. Le crieur parcourait alors les rues des villages en criant les nouvelles et les messages. Une information 'dernier cri' était donc une information nouvelle, d'où l'expression actuelle.

> ***EN*** : The expression "dernier cri" comes from the time when neither television nor newspaper existed. Exclusive information would be called out on the public place. The town crier would roam the streets, shouting news and messages. Therefore, a "dernier cri" (last shout) information was a new information. It gave the current expression.

  [1]: https://axiomcafe.fr/pourquoi-dit-on-dun-objet-quil-est-dernier-cri
  [2]: https://dictionary.cambridge.org/fr/dictionnaire/anglais/town-crier