CarrotsHaveEars

15 years ago is 2011 but you made it sound like 1911.

Besides all that, how would a doctor let you be dehydrated? If oral fluid is off the table, what stopped you from an intravenous one?

You are right. Using the word “increase” is highly unprofessional because it indicates causation. If we say the same thing scientifically correctly then the public would not even click on the title. ¯⁠\⁠_⁠(⁠ツ⁠)⁠_⁠/⁠¯

A study does not necessarily prove causation. Assume the study was not “hacked” to mislead the public and benefit the corporation, finding that A is related to B is enough to encourage a further study about it.

With “observational” studies, yes, but a formal study which has control over the study objects, and a vetting process to throw out dishonest samples accounts for that.