Just because it’s been a while.

Madama Butterfly. “Cio-Cio-San” is the heroine’s real name, while “Madame Butterfly” is a nickname.

I’ve read so many synopses of the opera that introduce the heroine as “Cio-Cio-San, nicknamed Butterfly,” “Cio-Cio-San, known as Madame Butterfly,” or some variation thereof. Actually, the two names are
one and the same. “Chouchou,” or “cho-cho” means “butterfly” in Japanese (“cio-cio” is the Italian spelling), while “san” is a title of respect, a la “Mr.” “Mrs.”… or “Madame.” This is presumably her professional name. Her birth name, in keeping with geisha tradition, is never mentioned.

Les Contes d’Hoffmann. Antonia dies of consumption.

This piece of fanon is very open to debate. Different scholarly writings I’ve read have disagreed on whether Antonia’s disease was probably meant to be TB or not. On the one hand, her symptoms don’t really reflect it. She never coughs, is depicted in-story as an outstanding singer (Pucciní’s Mimí never sings diegetically, while Verdi’s Violetta does only briefly in Act I), and most importantly, her illness is implied to be a heart disease, not a lung disease: its main outward sign is her often putting her hand to her heart. On the other hand, E.T.A. Hoffmann wrote the original story in 1819, before TB was even named, let alone very well understood. In those days, it was sometimes thought to be a heart disease, because science hadn’t confirmed it as a lung disease yet. So yes, it’s possible that Antonia suffers from a very stylized form of TB, but it’s just as easy to view her illness as a fictional one.

Die Zauberflöte. The Queen of the Night and her followers die in the end.

This is an easy assumption, since they’re obviously defeated and sing, “We plunge into eternal night!” Some productions explicitly kill them off: e.g. Jean-Pierre Ponnelle’s Salzburg staging, which had them fall down dead, or Benno Besson’s Paris staging, which had the Queen explode! But Schikaneder’s original stage directions only call for them to sink into the ground, which the Three Ladies did earlier with no lethal results, and Sarastro never says that the Queen will die when defeated, only “return to her castle.” Since she is the Queen of the Night, “We plunge into eternal night!” may just mean that the villains are forced to retreat forever to their own realm. At any rate, Wikipedia’s cast list for the opera’s obscure 1798 sequel Das Labyrinth (composed by Peter von Winter, Mozart being dead, but which can still arguably be called the “canon” sequel, since Schikaneder wrote the libretto and several singers from Flute’s premiere cast reprised their roles) reveals that the Queen, the Ladies and Monostatos return in the second work. Unless they appear as ghosts or visions of the past (I don’t know, having never read the libretto – is there anyone out there who saw the recent Salzburg production and can tell me?), I think we can safely assume that Schikaneder didn’t mean for them to die at the end of the original.

Die Zauberflöte. Papageno is the Queen’s illegitimate son.

I’ve read this theory in two books. Since Papageno never knew his mother, has no idea what happened to her, and is in the Queen’s employ, some commentators have “put two and two together.” But once again, Das Labyrinth apparently debunks this idea. Wikipedia’s brief summary reveals that the sequel has Papageno find his long-lost parents, who are listed as “Old Papageno and Papagena.”

Le Nozze di Figaro. The Count and Countess are middle-aged.

This assumption makes sense if you view Figaro as a stand-alone piece: the libretto never specifies their ages, we tend to associate crumbling marriages and cheating with middle age, and the Count is a baritone, a voice type usually associated with older characters. But it doesn’t work if you take both The Barber of Seville and the original Beaumarchais play into account. According to Beaumarchais, the Count and Countess have only been married for three years. But even ignoring the play, it doesn’t make sense for Figaro to take place too long after Barber. Figaro, whom we know is older than the Countess (in Barber he successfully passes himself off as her uncle), is only just getting married, Susanna is always portrayed as a pretty young thing, and there’s no indication that their romance is May-December, at least not by 18^th century standards. Besides, Mozart doesn’t seem to have associated the baritone voice with older men the way later composers have. His operas contain quite a few young baritone characters (e.g. Papageno in The Magic Flute, Guglielmo in Cosí Fan Tutte). I think it’s safe to assume that the Count and Countess are still in their twenties.