[Olog-hai]

Wrong. It was declared for all H₂O, not bottled water specifically; purveyors of bottled water were unfairly targeted too, because water does indeed relieve dehydration whether bottled or no, and no purveyor of bottled water ever claimed that their water was superior at relieving dehydration versus water from other sources nor claimed that only bottled water could relieve dehydration.

The EU is indefensible here, never mind on just about every point on subjects ranging far beyond this one.

[dr_lew]

Wrong. It was declared for all H2O, not bottled water specifically.

I find this:

However, last February, the European Food Standards Authority (EFSA) refused to approve the statement.

A meeting of 21 scientists in Parma, Italy, concluded that reduced water content in the body was a symptom of dehydration and not something that drinking water could subsequently control.

Now the EFSA verdict has been turned into an EU directive which was issued on Wednesday.

... which certainly supports your claim