Only, this statement doesn't hold up as the story progresses and is even faulty at the time of giving it.
Orochimaru views himself above Jiraiya yet admits Itachi is his superior.
Orochimaru likewise did better against 4T Naruto than Jiraiya did, this is an Orochimaru without the use of hand signs and was in a failing body as well.
So yeah, Itachi's statement was not and mostly isn't taken as fact. He's not about to 2v1 Kisame and Itachi and win nor is he superior to Itachi when Jiraiya's own rival admits defeat & Zetsu calls Itachi invincible when seeing a severely weakened version of him fight not ten minutes after Jiraiya and Pain fought.