If you don't want to translate that, the second ingredient in the listing is sugar. The second link says that 50% of French people add sugar to the plain yogurt they buy from the store.
0: https://www.carrefour.fr/p/yaourt-fruits-mixes-brasse-carref... 1: https://www.cerin.org/breves-scientifiques/quelle-quantite-d...
Sweet yoghurt is definitely not an American thing. Up until the last 10-15 years it was quite hard to find unsweetened yoghurt in either the UK or much of Europe. In France it was particularly hard as they seemed to prefer sweetened set yoghurt. In Spain that's still the default as of quite recently.
I remember when I lived in the United States, you basically had "fat free" (with lots of sugar) and "greek" (with a little bit of fat, in addition to the sugar). That was 20 years ago, so it might have changed since then.
It’s a study on Finnish children. It has nothing to do with Americans. I don’t know whether or not their yogurts tend to be sugary but nothing mentioned by anyone commenting on this thread has anything to do with the study.
This is a far better link with quotes from the researchers and others pointing out how this is extremely preliminary at best (not even peer reviewed yet, and even once it gets past peer review, it’s simply observational and cannot establish causation).
https://www.newsweek.com/type-1-diabetes-child-diet-nutritio...