Chemical principles dictate that the pH at the equivalence point of a titration depends on the strengths of the reacting acid and base, meaning it is not universally equal to seven.
The claim is a specific, empirical, well-established chemical fact: the equivalence point pH depends on the nature of the acid and base being titrated (e.g., weak acid-strong base titrations have equivalence points above pH 7). Papers 2 and 5 both support the principle that equivalence point pH varies according to the specific chemical system.