This just isn’t true. I worked at and built Poland springs water plant. Just water and ozone.
There is no fluoride in the Poland springs water it goes from wells to tanks to bottles. No fluoride is added. The add ozone to kill anything that shouldn’t be in the water. The ozone is what gives Poland springs water that nasty bitter taste.
Well I haven’t worked in the plants since the 90's so I guess it could be something new.