Plausible... for its time.
Main advantage for authoritarian government is destroying the general population's 'time binding'.
Oral history can so easily become urban legend, and vice-versa. Everyone believes what they're told, as there's nothing to gain-say the official position, and ignorance is bliss...
And, consider the medieval guilds, who strictly restricted their knowledge to *their* people. The Masonic Order are just an extreme example of resulting paranoia and compartmentalisation. Imagine if *everything* was as strictly unionised as eg Longshoremen or the infamous UK shipyards, where a rivetter could bring entire yard to halt by *moving* a scrap of copper pipe...