Often true in authoritarian times. The court jester or "fool" of old literature really did exist. At least in theory he was under the King's (Queen's) protection and could speak freely on any topic, even insulting honored guests etc. since nothing he said was to be taken serious, but in jest. This in an era when to merely insult the King or other important people would get your head chopped off or some other unpleasant outcome. The Fool was often a trusted advisor to his lord. Alas, the Fool’s immunity was not absolute and he did sometimes die for his impudence if he lost his lord’s protection. To some degree, our First Ammendment gives us much the same protection as a Fool in his prime enjoyed.

In a broader sense, the comment was already made that humor is a powerful tool to oppose tyranny. That is true and humor is one of many literary devices used in authoritarian times to say what would otherwise be unsayable in that culture.