For any who care, the idea of Noah being a preacher was common in the historic milieu that 2 Peter reflects. Josephus reports it (AJ 1.74), and an extensive description of it is in the non-canonical Jewish Sibylline Oracles (1.125-129, 148-198); it's also in numerous rabbinic works (like the one referenced above), and other early Christian authors (1 Clement 7.6; Theophilus, Ad Autol. 3.19; Apoc. Paul 50). Not that the WT writers know this or are allowed to share it, if they do.
Well, there's only one little problem with Josephus, and it's that Josephus was born in 37 CE, which means that writing about Noah being a preacher doesn't make his account any accurate. It just makes the fallacy older. He did not live any time near when Noah lived.
Along the same lines, the Sibylline Oracles are a collection of oracular utterances written in Greek, ascribed to the Sibyls, prophets who uttered divine revelations in a frenzied state. Fourteen books and eight fragments of Sibylline Oracles survive, in an edition of the 6th or 7th century. They are artistic work in a style that imitates that of the original Sibylline Books of the ancient Etruscans and Romans, which were burned by order of Roman general Flavius Stilicho in the 4th century. Again, the timing of the recollection only makes the fallacy older, not a reliable source of information.
Same thing with the works of any writer who lived during or after the Christian era. In other words, just because it's old doesn't mean that it's true, or that that the author can attest to those events.