Can I raise a practical point? Which is the time difference.
In news terms, the news is the commemoration of 9/11, so for example New York's "tribute of light". But because of the time difference that didn't happen in France until quite late, and news channels often take coverage from US networks. So there often isn't news footage until the 12th September. The problem then might become that it is so linked to the date of the event, that it seems like 'old' news if that makes sense.
Just by the by, almost a quarter of a million people died in the Boxing Day tsunami in 2004 - 75 9/11's in a single day. Tragedies are tragedies, ranking them seems almost futile - they become no less of a tragedy because they got 'trumped' by a worse one, if that makes sense.
The point is certainly made that the victims of this atrocity and their families are worthy of thought, sympathy and reflection. That is indisputable.