Tallinn (bigger city than Dunkirk) has free public transport since 2013, and since 2018 it expanded to the whole Estonia
https://www.weforum.org/agenda/2018/06/estonia-is-making-pub...
And the article states "Styling itself as a “laboratory” of free transport, Dunkirk has attracted an “incessant” stream of visitors intrigued at whether it could work in their cities, says Delevoye.". That's just poor journalism.
Everything else would have surprised me.