And? The glass has nothing to do with it. It's all about the bottle caps which can be made of plutonium for all I know. It's misleading to suggest that it has anything to do with the glass.
However, it is about bottle caps that are designed to go exclusively on glass bottles. I guess the headline could have read “Bottled drinks with caps that are designed to go on glass bottles ... ” That doesn’t seem like it would be misleading; it would also be less ambiguous than “bottle caps” which could suggest any cap to any bottle. (And it would be a rather obtuse way to phrase it.)
Regardless, the headline seems to be literally accurate. Microplastics are indeed found in larger quantities in glass-bottled drinks than in plastic-bottled drinks. Those microplastics in glass-bottled drinks come from the paint on the designed-for-glass-bottles bottle cap.
It is a public administrative body reporting to the Ministries of Health, the Environment, Agriculture, and Labour.
https://www.anses.fr/en/content/our-identity