I have no doubt that irony was as prevalant then as it is now, esopecially among subject peoples. Most people speaking Latin weren't Romans. (Now why does that thought sound familiar?)

Classical Latin used to go in for signalling the expected answer when asking questions. On the face of it this would seen to mark a rejection of irony - but no doubt this very factor would have been exlpoited by someone with an ironical intent.

"Am I not Modest?" - "Nonne impudicus sum?" (Expecting the answer "Yes".)

"Surely I am not pretentious?" "Num adrogans sum?" (Expecting the answer No.)